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[l/m 1/25/2007] Snakebite: Distilled Wisdom (11/28) XYZ

( Part1 - Part2 - Part3 - Part4 - Part5 - Part6 - Part7 - Part8 - Part9 - Part10 - Part11 - Part12 - Part13 - Part14 - Part15 - Part16 - Part17 - Part18 - Part19 - Part20 - Part21 - Part22 - Part23 - Part24 - Part25 - Part26 - Part27 - Part28 )
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TABLE OF CONTENTS of this chain:

See reader questions & answers on this topic! - Help others by sharing your knowledge
11/ Snakebite					< this panel >
12/ Netiquette
13/ Questions on conditions and travel
14/ Dedication to Aldo Leopold
15/ Leopold's lot.
16/ Morbid backcountry/memorial
17/ Information about bears
18/ Poison ivy, frequently ask, under question
19/ Lyme disease, frequently ask, under question
20/ "Telling questions" backcountry Turing test
21/ AMS
22/ Babies and Kids
23/ A bit of song (like camp songs)
24/ What is natural?
25/ A romantic notion of high-tech employment
26/ Other news groups of related interest, networking
27/ Films/cinema references
28/ References (written)
1/ DISCLAIMER
2/ Ethics
3/ Learning I
4/ learning II (lists, "Ten Essentials," Chouinard comments)
5/ Summary of past topics
6/ Non-wisdom: fire-arms topic circular discussion
7/ Phone / address lists
8/ Fletcher's Law of Inverse Appreciation / Rachel Carson / Foreman and Hayduke
9/ Water Filter wisdom
10/ Volunteer Work

Panel 11

	"There is in Melbourne a man who probably knows more about poisonous
	snakes than anyone else on earth.  His name is Dr. Struan Sutherland,
	and he has devoted his entire life to a study of venom.
	"'And I'm bored with it,' he said when we went along to see him
	the next morning.  'Can't stand all these poisonous creatures,
	all these snakes and insects and fish and things.  Stupid things
	biting everybody.  And THEN people expecting me to tell them
	what to do about it.  I'll tell them what to do.
	DON'T GET BITTEN IN THE FIRST PLACE.  That's the answer."
	"Hydroponics, now, that's interesting...."

	--Douglas Adams, Chapter 2 "Here Be Chickens," in Last Chance to See
		See further for "What about a tourniquet?"

Other relevant news groups:
	sci.bio.herp
	rec.pets.herp
        sci.med
        misc.emerg-services

A glossary of technical terms can be found at the end of this FAQ.

In Spanish:
http://www.montanismo.org.mx/articulos.php?id_sec=11&id_art=385&id_ejemplar=99

		TABLE OF CONTENTS

[These lines may not correspond in your news reader.]

Summary . . . . . . . . . . . . . . . . . . Line  121

Acknowledgments . . . . . . . . . . . . . . Line  174

References  . . . . . . . . . . . . . . . . Line  191

Introduction . . . . . . . . . . . . . . . .Line  257

Various Snakes and their Effects  . . . . . Line  321

Venoms  . . . . . . . . . . . . . . . . . . Line  367

Five Special Cases  . . . . . . . . . . . . Line  402

Nonvenomous Snakes .  . . . . . . . . . . . Line  491

Identification  . . . . . . . . . . . . . . Line  514
 Coral Snakes . . . . . . . . . . . . . . . Line  525
 Pit Vipers. . . . . . . . . . . . . . . . .Line  582
   Copperhead . . . . . . . . . . . . . . . Line  628
   Cottonmouth. . . . . . . . . . . . . . . Line  652
   Speckled rattlesnake . . . . . . . . . . Line  679
  The Three Nasties . . . . . . . . . . . . Line  700
   Eastern Diamondback  . . . . . . . . . . Line  730
   Western Diamondback  . . . . . . . . . . Line  773
   Mojave . . . . . . . . . . . . . . . . . Line  799

Epidemiology: The Risk of Snakebite . . . . Line  864

Prevention  . . . . . . . . . . . . . . . . Line  932

Envenomation . . . . . . . . . . . . . . . .Line 1011

Signs and Symptoms. . . . . . . . . . . . . Line 1045

Field Treatment . . . . . . . . . . . . . . Line 1103

Field Treatment: Areas of Disagreement. . . Line 1267

Field Treatment: 'Therapies' to Avoid . . . Line 1363

Hospital Care . . . . . . . . . . . . . . . Line 1467

Complications . . . . . . . . . . . . . . . Line 1515

Glossary  . . . . . . . . . . . . . . . . . Line 1541

Disclaimer .  . . . . . . . . . . . . . . . Line 1641


SUMMARY

Poisonous snakebite is a potentially serious accident.  It can lead to
severe pain or other problems, and in the rare instance even death. 
However in North America it is not nearly as dangerous as most believe. 
Snakes seldom bite humans and even when they do so, their bites are seldom
fatal.  There is no need to allow fear of snakes to ruin your enjoyment of
the outdoors. 

Snakes will usually avoid you if you give them a chance.  Try to be sure
they know you are coming. Don't reach into places they might hide. Be
careful turning over rock and boards in snake country.  Leave snakes
alone; there is no simple rule to identify which are poisonous.  The same
advice applies to dead snakes and detached heads - reflex bites are as
dangerous as bites from live snakes. 

At least half of all bites are caused by foolish behavior: handling or 
taunting venomous snakes, or failing to move away from a venomous snake 
once it has been sighted.

If someone is bitten:

The following treatment protocol is provided by Jeff Isaac and Peter Goth
in The Outward Bound Wilderness First Aid Handbook, Lyons and Burford,
1991.

"Transport the patient as quickly as possible to antivenin (antidote).
Although local discomfort may be severe, systemic signs and symptoms may
be delayed for two to six hours following the bite. Walking your patient
out is reasonably safe unless severe signs and symptoms occur. It is also
significantly faster than trying a carry. Splint the affected part if
possible. 

Expect swelling. Remove constricting items such as rings, bracelets, and
clothing from the bitten extremity. 

Do not delay. Immediately following the bite of a snake thought to be
poisonous, evacuation should be started. It can always be slowed down or
canceled if it becomes obvious that envenomation did not occur, or the
snake is not poisonous. 

Most medical experts agree that traditional field treatments such as
tourniquets, pressure dressing, ice packs, and "cut and suck" snakebite
kits are generally ineffective and are possibly dangerous. Poisonous
snakebite is one of those conditions that you cannot treat in the field.
Don't waste valuable time trying." 

If it is going to be more than one hour to transport, you should consider 
rinsing and disinfecting the wound.

      [End of Summary]


ACKNOWLEDGEMENTS

At the outset we would like to thank the following for their helpful 
comments and suggestions:

K.V. Kardong at the Dept. of Zoology, Washington State University
Keith Conover, M.D., Dept. of Emergency Medicine, University of Pittsburgh
loosemore-sandra@CS.YALE.EDU (Sandra Loosemore)
blazekm@a.cs.okstate.edu
pholland@iastate.edu (Paul Hollander)
KLEINSCHMIDT@MCCLB0.MED.NYU.EDU (Jochen)
CWA@NAUVAX.UCC.NAU.EDU (Curt Anderson)
ed@titipu.meta.COM (Edward Reid) 
Paul Moler, a professional herpetologist with the Florida Dept. of Game
  and Freshwater Fish. 


REFERENCES

This posting only scratches the surface.  The following sources will
provide more information: 

_The Outward Bound Wilderness First-Aid Handbook_ Jeff Isaac, P.A.-C. and 
Peter Goth, M.D. Lyons and Burford, 1991. Perhaps the best first aid book 
around at this time.

_Medicine for Mountaineering_, (referred to as 'MFM' throughout this
article)  Third Edition 1985.  James A. Wilkerson, M.D. ed.  The 
snakebite section starts on p234.  The section on treatment is now 
somewhat dated. 

_A Field Guide to Western Reptiles and Amphibians_, Robert C. Stebbins,
Houghton Mifflin, 1966.  A good guide to snakes and other reptiles
including descriptions, color illustrations and maps of their ranges. 
Part of the Peterson Field Guide Series. Covers only the western U.S. 

_Rattlesnakes_, Laurence M. Klauber, University of California Press, 1982. 
This is a condensation of a 2 volume series on the same topic.This book
does not provide as much identification information as does Stebbins, but
it does include range maps. It provides a lot of interesting information
about many topics ranging from the snake life cycle to collections of
folklore and misinformation. 

Russell, Findlay E. 1980. _Snake venom poisoning in the United States_, 
Annual Review of Medicine, 1980, 31:247-59.

Kurecki, Barnard A. and H. James Brownlee._Venomous snakebites in the 
United States_, The Journal of Family Practice, 1987, 25(4):386-92.

Gold, Barry S. and Willis A. Wingert._Snake venom poisoning in the United 
States: A review of therapeutic practice_, Southern Medical Journal, June 
1994, 87(6):579-89.

Downey, Daniel J., George E. Omer, and Moheb S. Moneim._New Mexico
rattlesnake bites: Demographic review and guidelines for treatment_, The
Journal of Trauma, 1991, 31(10):1380-86. 

Curry, Steven C. et al., _The legitimacy of rattlesnake bites in central 
Arizona_, Annals of Emergency Medicine, 1989, 18(6):658-63.

Iserson, Kenneth V._Incidence of snakebite in wilderness rescue_, Journal 
of the American Medical Association, Sept 9, 1988, 260(10): 1405. 

Antivenin (Crotalidae) Polyvalent under Wyeth-Ayerst Laboratories, in
_Physicians Desk Reference_, Medical Economics Data: Montvale, NJ. 1995.

Antivenin (Micrurus fulvius) under Wyeth-Ayerst Laboratories, in
_Physicians Desk Reference_, Medical Economics Data: Montvale, NJ. 1995.

Berkow, Robert (ed)._The Merck Manual of Diagnosis and Therapy. 14th 
Ed._, Merck, Sharpe and Dohme: Rahway, NJ, 1982.

J.L. Behler and F. Wayne King. _The Audubon Society Field Guide to North 
American Reptiles and Amphibians_. Alfred A. Knopf: New York, 1979.

_Conant, R. 1975. A field Guide to Reptiles and Amphibians of
Eastern and Central North America_, Houghton Mifflin Company;Boston.
Covers the eastern U.S. but there is also a Western edition by Stebbins 
(see above).

Minton, Sherman A. Poisonous Snakes and Snakebite in the U.S.: A Brief 
Review. Northwest Science, 61(2): 130-37, 1987.

INTRODUCTION

Snakebite is always a hot topic.  In what follows we will attempt to
describe prevention and treatment of bites by poisonous snakes in North
America as well as the effects of such bites.  Be aware that we are
dealing with overreaction and hype here.  Popular literature, folklore,
and movies have greatly exaggerated both the probability of snakebite and
the likely outcome should it happen. Humans are much less likely to get
bitten than many people believe.  Furthermore snakebite, while
serious, is not the death sentence often implied.  Snakes, poisonous and
otherwise, have excited a lot of aversion and superstition over the ages,
resulting in unwarranted fear and sometimes even panic.  This fear and 
panic can lead to: 

   Improper treatment of those cases which need treatment for 
   envenomation.

   Dangerous overtreatment for bites in which envenomation does not
   occur.
   
   Worsening the outcome of snakebites due to panic.
   
   Unnecessary and dangerous treatment of bites by nonvenomous
   snakes.  

   Unnecessary, expensive, and dangerous rescue operations.

   Unnecessary destruction of snakes and their habitat.   

Snakebite in the U.S. should be treated conservatively.  There is no need
to jump in with knives, tourniquets, ice, or compression bandages. There
is no need to try to suck out the venom by mouth. Carrying out any of
these extreme procedures has the potential to do far more harm than good. 
We will explain later in this FAQ the reasons that such extreme measures
do not form part of the therapy for snakebite. Victims should be given
only the appropriate treatment and then be rapidly evacuated to medical
facilities. 

Wilkinson in Medicine for Mountaineering has this to say,

  "About no other medical subject has so much been written when 
  so little has been known!"

  "Poisonous snakebites are unquestionably serious, potentially
  deadly accidents.  Nonetheless, the danger from a single bite 
  has been greatly exaggerated, particularly in the United States, 
  where an average of less than fifteen people die each year as 
  the result of bites by poisonous snakes.  Less than one percent 
  of poisonous snakebites in this country are lethal.  In other 
  parts of the world poisonous snakes are a more serious problem. 
  Many of the snakes in those areas have a much more toxic venom, 
  treatment is less successful, and sophisticated medical care is 
  less available."  (MFM p234)

Of course severity will vary with species as well as with the individual
snake. Larger snakes of the same species tend to have more venom (although
the larger snake may have learned to ration its venom while a younger
animal may be more likely to inject the full load).  In North America we
do not have the really nasty varieties of snakes found in some parts of
the world.  There is no reason to panic when someone is bitten by a snake. 
Even the "three nasties" described below are not nearly as dangerous as
the cobras, black mambas and death adders found outside the U.S. 


VARIOUS SNAKES AND THEIR EFFECTS:

Venomous snakes in the U.S. all belong to one of two families:

   Crotalids (pit vipers):
      copperhead
      cottonmouth or water moccasin
      the numerous species of rattlesnakes

   Elapids
      coral snake (eastern and Arizona species)

Crotalids have the most efficient injection mechanism of any snake.  They
are equipped with long hollow fangs and a system to inject venom through
those fangs. They have the ability to inject large volumes of venom
quickly.  Crotalid fangs can fold back into the mouth; lack of visible
fangs does not necessarily mean an unarmed snake. Most crotalids have
venom that is less toxic than that of coral snakes.  Crotalids, however,
are the more dangerous group because (a) they are more likely to bite a
human, (b) they can inject venom much more efficiently, and (c) they are
usually larger and have more venom to use. 

Elapids on the other hand have grooved fangs. This is a much less
efficient injection mechanism.  They chew to get the venom into the
victim.  The size of coral snakes limits them to biting fingers or loose
folds of skin. The elapidae include some of the world's nastiest critters:
the black mamba, the death adder, and the cobra. 

The two species of coral snakes in North America are about as mild as
poisonous snakes can be.  They are not aggressive. Children have
reportedly played with coral snakes for hours without being bitten, but no
record exists of how many parental heart attacks this has caused! The
venom is potent, however, and treatment should be given for bites which do
occur.  Coral snake bites make up less than 2% of all U.S. snakebites. In
fact, Gold and Wingert report that fewer than 25 of all reported venomous
snakebites per year are from coral snakes.  There have been no known
fatalities from coral snake bites since the development of the _Micrurus
fulvius_ antivenin (Wyeth-Ayerst Laboratories). 

The Arizona coral snake (Micruroides euryxsanthus) is less dangerous than
the eastern coral snake (Micrurus fulvius).  It is smaller and would have
a hard time biting a person even if inclined to do so.  The rare bites
which do occur should be treated the same as bites from the eastern coral
snake. 


VENOMS:

Snake venom usually contains two types of poison: hemolytic toxins which
attack the walls of blood vessels and neurotoxins which attack the nerves. 
  
Hemolytic toxin attacks blood vessel walls, allows serum to escape into
the surrounding tissues, and causes clotting within the vessels.  The
result is severe swelling, pain, and discoloration at the site of the
bite.  In the few cases where hemolytic toxins cause death, the actual
cause is likely to be shock.  The effects of hemolytic toxin are immediate
and primarily localized.  Symptoms will be obvious. 

Neurotoxins produce much less obvious immediate symptoms, at times fooling
the victim into believing envenomation has not occurred.  But systemic
symptoms can appear later.  Neurotoxins produce much less local reaction
than do hemolytic toxins.  On the other hand, they can affect nerves quite
removed from the site of the bite.  In extreme cases they can cause
respiratory arrest, although this is uncommon with the bites from most
North American snakes.  However, respiratory distress without actual
arrest may to occur in neurotoxin victims.  Less severe symptoms from
neurotoxins include tingling or prickly feelings and eyelid paralysis. 

All snake venom probably has some of each kind of toxin. But, most pit
vipers have a higher fraction of hemolytic toxin, and  elapids have more
neurotoxin.  The Mojave rattlesnake, a pit viper, is an exception; see
below. The potency of venom will vary, with species, with time of year and
with geographic area.  

The typical snake mouth is no cleaner than a human's. So, they tend to
induce microbial contamination into bites.  Although it is common for a
snake to bite without injecting venom, microbial contaminants will always
be present and should always be treated. Such contamination seems to be
much less of a problem in bites by nonvenomous snakes, perhaps because
their bites do not penetrate so deeply. 

FIVE SPECIAL CASES: 

FIVE varieties deserve special mention:  A single bite from a copperhead
is not very dangerous. The diamondbacks (eastern and western species) and
the Mojave rattlesnakes deserve attention because they are particularly
dangerous. The speckled rattlesnake should also be mentioned because bites
from it, like those from the Mojave, may not produce local pain or other
reaction. (It is worth noting, however, that Findlay Russell points out
that pain is not always associated with an envenomated bite from any
variety of snake). 

The copperhead has probably the mildest venom of any poisonous snake in
the U.S.  Adults bitten by a single copperhead usually need only
supportive therapy and good cleansing and disinfection of the wound.  A
study of 400 victims of copperhead bites found only 2 deaths, both the
result of simultaneous bites by 3 or more snakes. About 3,000 bites a year
are inflicted by copperheads.  You would probably want treat a copperhead
bite pretty much as any other pit viper bite, but would be able to
reassure the patient a bit more and would not be as concerned if medical
help were not readily available.  This not to say that a copperhead bite
won't hurt, it will.  These bites are still serious but are unlikely to be
life threatening. Gold and Wingert state that "It [antivenin] is 
unnecessary in most cases of copperhead bite and pygmy rattlesnake bites.

The diamondbacks, on the other hand, are potentially deadly.  Both
the eastern and western versions are huge, the western species
compensating for its slightly smaller size with a more potent venom.
MFM lists the eastern diamondback as an aggressive snake and claims
it is responsible for more human deaths than any other U.S. snake.
Others dispute this.  Paul Moler argues it is not particularly
aggressive and quotes some numbers which indicate that it is unlikely
to lead in killing people. 

The Mojave rattler is dangerous in spite of its size.  This little rascal
is armed with a very potent venom, high in neurotoxins. Pain and other
local responses to the bite may be mild, but the systemic response may be
marked.  Initial reaction is usually mild with severe symptoms coming 12
to 16 hours after the bite.  The early symptoms could easily fool one into
believing there was no problem.  By the time severe symptoms appeared the
best time for treatment would have passed.  The Mojave rattlesnake also
has a couple of close relatives south of the border, the Mexican west
coast rattler and the South American tropical rattlesnake, also known as
cascabel or neotropical rattlesnake.  They provide problems at least equal
to those of the Mojave version. 

It is worth mentioning that bites from other North American venomous
snakes may yield little local pain, swelling, or other reaction following
envenomation. This true of bites from the speckled rattlesnake,_Crotalus
mitchelli_, and possibly also of bites from the rock rattlesnake,
_Crotalus lepidus_, and tiger rattlesnake, _Crotalus tigris_ (Minton,
1987).  If you know that you have been bitten by one of these snakes, it
is probably best to assume that you have been envenomated and procede to a
hospital. 

Envenomated bites from either the diamondback or the Mojave rattler are
serious, possibly even deadly. Do your level best to evacuate the victim
quickly to medical facilities. 

There is of course a wide variety of poisonous snakes throughout the
world.  We can't discuss them all here.  They are generally confined to
warmer climates in places such as Australia, Africa, the Indian
subcontinent, and Southeast Asia. Many of these snakes much more dangerous
than those native to the North America.  There are some exceptions with
more northerly ranges. For example, the habitat of the European viper
extends to the Arctic Circle. It is not, however, as dangerous as some of
the snakes inhabiting warmer climates.  If you plan to engage in
wilderness activities overseas you should research their venomous snakes. 

MFM does have some information on other areas as well as a list of central
medical facilities which can provide more information.  If you are not
familiar with the snakes in an area, assume they are dangerous (especially
in warm climates). If you are bitten by an exotic snake in the U.S. (a
pet, a zoo specimen, or a research specimen) your physician will want to
contact a referral center for information on treatment and antivenin
availability.
There are numerous relevant entries in a list at URL
<http://www.desertusa.com/mag98/mar/stories/rattlein2.html>, including
one for the referenced center:

     ARIZONA POISON & DRUG INFORMATION CENTER
     Arizona Health Sciences Center, Room #1156
     1501 North Campbell Avenue
     Tucson, AZ 85724
     Emergency Phone: (800) 362-0101 (AZ only)
     (520) 626-6016
     Administrative Phone: (520) 626-7899
     FAX: (520) 626-2720
     E-MAIL: tong@pharmacy.arizona.edu
     Website:
http://www.Pharmacy.Arizona.EDU/centers/poisoncenter/apdicindex.html
(Note that the 1-800 number is limited to in-state calls only.)
	the Oklahoma City Zoo (405-424-3344),
	the Rocky Mountain Poison Center (303-629-1123), or
	the New York City Snakebite Emergency Center (718-430-6494). 

If your physician desires more information on the two antivenins used for 
the treatment of North American snakebites, he can contact the manufacturer:

Professional Service
Wyeth-Ayerst Laboratories
PO Box 8299
Philadelphia, PA 19101
(610) 688-4400, or
(800) 950-5099

NONVENOMOUS SNAKES

Snakes regarded as nonvenomous are not necessarily completely safe. The
saliva of many of these snakes can contain the same toxins as the venom of
their more feared relatives.  Some snakes such as the gopher snake lack
anything resembling venom, and others such as the hognose and garter
snakes have saliva which could be considered a mild venom.  After all,
true snake venom is just modified saliva anyway. These so-called
nonvenomous snakes lack an efficient means of delivering their
saliva/venom to a human victim. Yet there are recorded cases of them
envenomating and even killing people.  The victims tend to be people who
regularly handle snakes either professionally or as a hobby. 

The most common reaction to such a bite (at least in the
U.S.) is the swelling, pain, and discoloration caused by hemolytic
toxins.  But neurotoxins have also been identified in the saliva
of some of these snakes.

More information on this subject can be found in several references. One
we were able to locate was, Sherman A. Minton, Jr. "Beware:  Nonpoisonous
Snakes," _Natural History_, 87: 56, Nov 1978. 


IDENTIFICATION:

Rule One:  Leave snakes alone.  There is no reliable rule to distinguish
which snakes are venomous and which are not.  Characteristics vary greatly
depending on locale and occasional individuals have atypical coloration or
pattern.  

Rule One, Expanded: Unless you are engaged in legitimate biological
research, leave undisturbed all wildlife you encounter in the wilderness. 


Coral Snakes

It is useful to be able to identify the dangerous species of
snakes.  However it is not always easy.  Coral snakes are probably
the easiest to properly identify, they are small (usually no more
than about 30 inches long, sometimes up to 40 inches), thin,
brightly colored, and have small heads.  They can be distinguished from 
the nonvenomous king snake and other harmless mimics by the presence 
of adjacent red and yellow bands. Milk snakes, king snakes, and the other 
mimics have adjacent red and black bands:

   Red touch yellow - kill a fellow
   Red touch black - venom lack.

Another mnemonic is to think of a traffic light.  If red is adjacent
to yellow, stop!

There are two species, the Arizona coral snake (Micruroides euryxanthus) 
and the eastern coral snake (Micrurus fulvius).

Bebler and King describe the Arizona coral snake (Micruroides euryxanthus)
as follows: 

"Description: 13-21 inches. Blunt-snouted and glossy, with alternating
wide red, wide black, and narrow yellow or white rings encircling the
body. Head uniformly black to angle of jaw. Scales smooth, in 15 rows.
Anal plate divided. 

Habitat: Rocky areas, plains to lower mountain slopes; rocky upland 
desert especially in arroyos and river bottoms; sea level to 5900 feet. 

Range: C. Arizona to sw New Mexico south to Sinaloa, Mexico.

This snake emerges from a subterranean retreat at night, usually during 
or following a warm shower. When disturbed by a predator, it buries its 
head in its coils, raises and exposes the underside of its tail, and may 
evert its cloacal lining with a popping sound. Eats blind snakes, other 
small snakes."

Bebler and King describe the eastern coral snake (Micruroides fulvius) as
follows: 

"Description: 22-47 inches. Body encircled by wide red adn black rings 
separated by narrow yellow rings. Head uniformly black from tip of blunt 
snout to just behind eyes. Red rings usually spotted with black. Scales 
smooth and shiny in 15 rows. Anal plate divided. 

Habitat: Moist, densely vegetated hammocks near ponds or streams in 
hardwood forests; pine flatwoods; rocky hillsides and canyons.

Range: Se. North Carolina to s. Florida and Key Largo, west to s. Texas 
and Mexico.

Usually seen under rotting logs or leaves or moving on surface in early 
morning or late afternoon. Feeds on small snakes or lizards."


Pit Vipers

Pit vipers are a bit more difficult.  Of course the presence of rattles
tells you that you are dealing with a venomous snake, but absence thereof
gives no assurance to the contrary.  Copperheads and cottonmouths have no
rattles, and even rattlers sometimes loose their rattles.  The presence of
fangs indicates a venomous snake, but these may be folded back in the
mouth and difficult to detect. The fangs may even be broken off.  The
easiest indicator (but one which requires practice, maybe in a zoo) is the
characteristic heavy body and triangular head of the pit viper.  Although
some nonvenomous snakes also have these characteristics it is always best to
treat a snake with caution.

In a dead snake you could look for the pit after which the pit viper is
named.  This will be between the eye and nostril, one on either side of
the head. Another sure indicator is the scales behind the anal plate.  Pit
vipers have a row of single scales reaching across the underside of their
bodies behind the anus while most other snakes have a double row of
scales, joining in about the middle.  Some references suggest checking the
pupils of the snake's eyes for identification.  Pit vipers will have
vertical slit pupils.  If the snake has round pupils it is not a pit
viper.  These fine characteristics are probably only useful in identifying
a dead snake. One wouldn't want to pick up a live one to look at its
underscales or its pupils. 

One good indicator of the type of snake is the location.  Snakes don't
wander far from home. They tend to have a limited range and will not
survive outside the conditions they prefer.  Except in the case of an
exotic pet you will not find them in areas far removed from their normal
range.  You simply won't find a Mojave rattler in Ohio or an eastern
diamondback in Colorado.  Several of the books listed above describe the
ranges for various species, usually with maps. 

Body markings are rarely sufficient for identification by the
inexperienced.  It takes a lot of practice to learn to distinguish between
various species, some of which are quite similar externally.  Furthermore,
individuals of the same species can have varying shades of color, making
such identification even more difficult.  See the references listed above
for pictures and other help in identification.  If you are concerned about
venomous snakes, get a book on herpetology and study it.  Visit zoos and
talk with specialists.  You will not become an expert by reading usenet. 

Again, the best rule is, leave snakes alone!  Getting close enough to
identify pits or scales is dangerous.  You might then be able to also
examine the fang marks on your body! 

Copperhead

Bebler and King describe the copperhead (Agkistrodon contortrix) as
follows: 

"Description: 22-52 inches. Stout-bodied; copper, orange, or pink-tinged,
with bold chestnut or reddish-brown crossbands constricted on midline of
back. Top of head unmarked. Facial pit between eye and nostril. Scales
weakly keeled, in 23-25 rows. Anal plate single. 

Habitat: Wooded hillsides with rock outcrops above streams or ponds; 
edges of swamps and periodically flooded areas in coastal plain; near 
canyon springs and dense cane stands along the Rio Grande; sea level to 
5000 feet.

Range: Sw. Massachsetts west to extreme se. Nebraska south to Florida 
panhandle and sc. and west to Texas.

It basks during the day in spring and fall, becoming nocturnal as the 
days grow warmer. Favored summer retreats are stonewalls, piles of debris 
near abandoned farms, sawdust heaps, and rotting logs, and large flat 
stones near streams.... In fall, copperheads return to their den site, 
often a rock outcrop on a hillside with a southern or eastern exposure."

Cottonmouth

Bebler and King describe the cottonmouth or water moccasin (Agkistrodon 
piscivorus) as follows:  

"Description: 20-74 inches. A dark, heavy-bodied water snake; broad-based
head is noticeably wider than neck. Olive, brown or black above;
patternless or with serrated-edged dark crossbands. Wide light-bordered,
dark brown cheek stripe distinct, obscure, or absent. Head flat-topped;
eyes with vertical pupils (not visible from directly above as are eyes of
harmless water snakes); facial pit between eye and nostril. Young strongly
patterned and bear bright yellow tipped tails. Scales keeled, in 25 rows. 

Habitat: Lowland swamps, lakes, rivers, bayheads, sloughs, irrigation 
ditches, canals, rice fields, to small clear rocky mountain streams; sea 
level to ca. 1500 feet.

Range: Se. Virginia south to upper Florida Keys, west to s. Illinois, s. 
Missouri, sc. Oklahoma and c. Texas. Isolated population in nc. Missouri.

When annoyed, the cottonmouth tends to stand its ground and may gape 
repeatedly at an intruder, exposing the light cotton lining of its mouth. 
Also called trap jaw or water moccasin. Unlike other water snakes, it 
swims with head well out of water. Although it may be observed basking 
during the day, it is more active at night. Preys on sirens, frogs, 
fishes, snakes, and birds."

Speckled Rattlesnake

Bebler and King describe the speckled rattlesnake (Crotalus mitchelli) as
follows:  

"23-52 inches. Pattern and color vary greatly; generally has a sandy, 
speckled appearance. Back marked with muted crossbands or hexagonal to 
diamond shaped blotches formed by small clusters of dots. Large scale 
above eye ptted, creased, or rough-edged; or rostral scale separated from 
preanals by row of tiny scales. Scales keeled, in 23-27 rows.

Habitat: Prefers rugged, rocky terrain, rock outcrops, deep canyons, 
talus, chaparral amid rock piles and boulders, rocky foothills; sea level 
to 8000 feet. 

Range: Extreme sw. Utah, s. Nevada and s. California south into nw. 
Sonora and throughout Baja California.

Active during the day in spring and fall, at night in summer. Eats ground 
squirrels, kangaroo rats, white-footed mice, birds, and lizards."

The Three Nasties

There are three species worth extra attention if you frequent their
ranges.  These all have the venom to make you pay dearly should you upset
them.  Different sources give different assessments of the dispositions of
the eastern diamondback and the Mojave rattler. Some list them as short
tempered and quick to strike humans, while others say that they are not
very aggressive.  There is, however, general agreement that both of these
plus the western diamondback pack a nasty wallop if they do bite.  It is
useful to know if you are in their range and be able to recognize them in
order to get proper treatment should someone get bitten. 

While a major distinguishing feature of both diamondbacks (at least in the
adult snake) is their size, this may be an unreliable indicator.  Even
experts have a difficult time estimating the size of a live snake, a
problem compounded when a novice unexpectedly encounters one.  Size
estimates are typically quite generous to say the least.  If the snake is
dead and can be measured you can get useful information.  Most of the
danger of a diamondback comes from its size and the quantity of venom
anyway.  It won't make much difference if it is a juvenile diamondback or
an adult of some other species (except the Mojave). 

Various authors do not agree on which is the most dangerous.  Some claim
this honor for the eastern diamondback, and some for the western version. 
The eastern species is larger and has more venom but its western cousin
has a more potent venom.  The Mojave rattlesnake is also a good candidate
for the most dangerous snake in the U.S Its very potent venom with the
delayed action make it a real danger.  Not that it matters much, one would
not want to be bitten by any of the three. 

Eastern Diamondback (Crotalus adamanteus)

According to Conant's Reptiles & Amphibians of Eastern/Central U.S. ,
"33-72 inches; record 96 inches [Bebler and King give the range as 36 to
96 inches]. An ominously impressive snake to meet in the field. The
diamonds, dark brown or black in color, are strongly outlined by a row of
cream-colored or yellowish scales.  Ground color olive, brown, or almost
black.  Pattern and colors vivid in freshly shed specimens; dull and quite
dark in those preparing to shed.  Only rattler within its range with 2
prominent light lines on face and vertical light lines on snout. 
	
At home in the palmetto flatwoods and dry pinelands of the South. 
Occasionally ventures into salt water, swimming to outlying Keys off 
the Florida coast.  Some snakes will permit close approach without 
making a sound, whereas others, completely concealed in palmettos or 
other vegetation, will rattle when dogs or persons are 20 or 30 feet 
away.  Many stand their ground, but when hard pressed they back away,
rattling vigorously but still facing the intruder.  Frequently they 
take refuge in burrows of gopher tortoises, in holes beneath stumps, 
etc.  Rabbits, rodents, and birds are eaten.
	
Range:  Coastal lowlands from se. N. Carolina to extr. E. Louisiana; 
all of Florida, including the Keys."

According to Behler and King's Audubon herpetology guide:

"Our largest rattler.  Heavy-bodied with large head sharply distinct
from neck.  Back patterned with dark diamonds with light centers and
prominently bordered by a row of cream to yellow scales.  Prominent 
light diagonal lines on side of head.  Vertical light lines on snout.  
Scales keeled, in 27-29 rows."

Range and habitat same as above, but get this,

"Give it a wide berth; most dangerous snake in North America! Venom
highly destructive to blood tissue. Stumpholes, gopher tortoise burrows, 
and dense patches of saw palmetto often serve as retreats.  Their 
numbers have been substantially reduced by extensive land development 
and by rattlesnake hunters. Eats rabbits, squirrels, birds"	

The following descriptions of the Mojave and western diamondback are taken 
from Stebbins's book:

Western Diamondback Rattlesnake (Crotalus atrox)

"Identification:  30-89 inches.  The largest western rattlesnake.
Above:  gray, brown or pink with brown diamond or hexagonal blotches
on the back and fainter smaller blotches on the sides.  Markings
often indefinite and peppered with small dark spots, giving an
overall speckled or dusty appearance.  Tail set off from the rest of
the body by broad black and white rings, about equal in width; hence
sometimes called the "coontail" rattler.  A light diagonal stripe
behind the eye intersects the upper lip well in front of the corner
of the mouth.  Young:  9-14 inches, markings more distinct than in
adult.

Frequents a variety of habitats in arid and semiarid regions from
the plains into the mountains - desert, grassland, brushland,
woodland, rank growth of river bottoms, rocky canyons, and lower
mountain slopes.  Crepuscular and nocturnal, but also abroad in
daytime.  Perhaps the most dangerous North American serpent, often
holding ground and boldly defending itself when disturbed.
Live-bearing.

Range:  SE California to E Oklahoma and E Texas, south to Isthmus of
Tehauantepec.  Old records for central Arkansas and Trinidad, Las
Animas Co., Colorado.  Sea level to 7000 feet."


Mojave Rattlesnake (Crotalus scutulatus)

"Identification:  24-51 inches.  Well-defined, light-edged dark gray to 
brown diamonds, ovals, hexagons down middle of back; light scales of
pattern usually entirely light-colored.  Ground color greenish gray, 
olive green, brownish, or yellowish.  A white to yellowish stripe 
extends from behind the eye to a point behind the corner of the mouth 
except at extreme southern end of range.  Tail with contrasting light 
and dark rings; dark rings narrower than light rings. Enlarged scales 
on snout and between the supraoculars.

Chiefly inhabits upland desert and lower mountain slopes, but ranges to
about sea level near the mouth of the Colorado river and to high
elevations in the Sierra Madre Occidental.  Habitats vary--barren desert,
grassland, open juniper woodland, and scrubland.  This rattler seems to be
most common in areas of scattered scrubby growth such as creosote bush and
mesquite.  Not common in broken rocky terrain or where vegetation is
dense.  Eats kangaroo rats and other rodents; and probably other reptiles. 
AN EXTREMELY DANGEROUS SNAKE; EXCITABLE AND WITH HIGHLY POTENT VENOM. 

Range--S. Nevada to Puebla, near southern edge of Mexican Plateau; 
western edge of Mojave Desert, Calif. to extreme w. Tex.  From near sea 
level to around 8300 feet."

In case of a bite it may be important to distinguish between the
diamondback and the Mojave.  The ranges of the species overlap and if you
are in the area of overlap you may not know which was the culprit.  The
distinction is important in the case of a bite with little or no local
reaction.  In a diamondback bite, lack of reaction within 4 to 6 hours
indicates that envenomation did not occur.  However if a Mojave was the
culprit no such assumption can be made and systemic reaction may occur
12-16 hours later.  The two species are very similar in appearance.  The
relative width of light and dark tail bands may be the best way to
distinguish between the two.  If uncertain, assume the snake was a Mojave
and treat accordingly. 

Other similar snakes include the speckled and western rattlesnakes
(there are several sub-species of the speckled).  Their ranges also
overlap those of the Mojave and diamondback.  

Mojave venom can be up to 20 times the as potent as diamondback venom,
although its quantity will typically be about 1/6 that of a diamondback.
Specific references to Mojave and its unusual venom are: 

_The Venomous Reptiles of Arizona_, (Arizona Game and Fish) pp 55-56.

_Journal of Herpetology_, Vol 23 no. 2, pp 131ff (1989)

_Herpetologica_, vol 47 No. 1 (March 1992) pp 54ff

One other note on the Mojave:  There is a central Arizona version which
can be considered a subspecies.  The principal difference between it and
its more widely distributed cousins is that its venom is very similar to
diamondback venom.  This therefore makes it less dangerous than other
Mojaves.  There are also hybrids which have components from both venom
types.  Hybrids present the particular danger of a local reaction which
may fool victims and medical personnel into believing the culprit was a
some other rattler until the systemic reaction due to neurotoxin sets in
later.  Even experts can't tell the difference between different varieties
of Mojave except by analyzing the venom. 

There are a number of other species of rattlesnakes in North America. 
Information on their identification can by found in the Peterson or 
Audubon field guides.

EPIDEMIOLOGY: THE RISK OF SNAKEBITE

Your risk of being bitten be a snake is small, and so too is your risk of 
dying if bitten. Findlay E. Russell writes in Ann Rev Med 1980, 31:247-59., 

"Although there are an estimated 45,000 bites by all snakes in the United 
States each year, only about 6680 persons are treated for snake venom 
poisoning. However, it can be expected that at least 1000 additional 
bites by venomous snakes occur each year and that they are either not 
treated or go unreported. During the past five years, the number of 
deaths from snakebite in the United States has ranged between 9 and 14. 
Most of the deaths occurred in children, in the elderly, in untreated, 
mistreated, or undertreated cases, in cases complicated by other serious 
disease states, or in members of religious sects who handle serpents as 
part of their worship exercises and refuse medical treatment. Almost all 
reported deaths have been attributed to rattlesnakes."

In a second  article (When a snake strikes, Emergency Medicine, 1990, 
22:21-43.), Russell states,

"25% of all pit viper bites do not result in envenomation and another 15% 
are so trivial, they require only local cleansing and tetanus 
prophylaxis."

Kurecki and Brownlee write in The Journal of Family Practice 1987 
25(4):386-392,

"Approximately 75 percent of all snakebites occur in people aged between 
19 and 30 years, 1 percent to 2 percent occur in women, and less than 1 
percent occur in blacks. Approximately 40 percent of all snakebites occur 
in people who are handling or playing with snakes, and 40 percent of all 
people bitten had a blood alcohol level of greater than 0.1 
percent. Sixty-five percent of snakebites occur on the hand or fingers, 
24 percent on the foot or ankle, and 11 percent elsewhere. One case was 
reported of a snakebite on the glans penis."

So it seems that getting drunk and messing about snakes is a big cause of
getting bitten. It also seems that male yahooism is a precursor to snake
toxin poisoning. Women are unlikely to get themselves bitten, and if they
do get bitten, it is unlikely that they got that way by doing something
stupid. Here is some more interesting data on that point from Curry et al.
in Annals of Emergency Medicine 1989 18(6):658-63: 

"We reviewed medical records of 85 consecutive snakebite victims cared 
for at a single medical center to determine legitimacy of snakebites. A 
bite was considered illegitimate if, before being bitten, the victim 
recognized an encounter with a snake but did not attempt to move away 
from the snake. A legitimate bite was said to have occurred if a person 
was bitten before an encounter with a snake was recognized or was bitten 
while attempting to move away from a snake. The study group was made up 
of 75 male (87.2%) and 11 female (12.8%) victims. Seventy-four percent 
were 18 to 50 years old, and 15% had been bitten previously. Only 43.4% 
of all bites were considered legitimate, and pet (captive) snakes 
accounted for almost one third of all illegitimate bites. The ingestion 
of alcoholic beverages was associated with 56.5% of illegitimate bites 
versus 16.7% of legitimate bites. While 74.4% of bites were to upper 
extremities, only 27% of upper extremity bites were legitimate. All 
bites to the lower extremities were legitimate. Of 14 individuals bitten 
by pet snakes, all were men and 64.3% were under the influence of alcohol 
at the time of the bite. In our patient population, the data suggest that 
a 16% reduction in rattlesnake bites would result if rattlesnakes were 
not kept as pets, and more than one half of all rattlesnake bites would 
be eliminated if persons simply would attempt to move away from a 
rattlesnake after an encounter is recognized".  

It is worth noting that only one woman in Curry et al.'s study group received
an illegitimate bite.

PREVENTION:

Obviously the best prevention is to avoid getting bitten.  It helps that
humans are not the natural prey of any venomous snake.  We are a bit large
for them to swallow whole and they have no means of chopping us up into
bite size pieces.  Nearly all snakebites in humans are the result of a
snake defending itself when it feels threatened.  In general snakes are
shy and will simply leave if you give them a chance. Remember, MOST BITES
HAPPEN TO PEOPLE WHO FAIL TO MOVE AWAY FROM SNAKES ONCE THEY SEE THEM. So
don't pick up, torment or otherwise mess about with venomous snakes. In
light of the Curry data, avoiding alcohol or drug intoxication in snake
country would be a good idea.  Many, many bites are associated with
intoxication. 

Another basic rule is to be sure the snake knows you are coming.  Walk
heavily; they may sense ground vibrations better than sound.  If they
sense your presence they will almost always leave before you even know
they are there.  (This may not apply in other parts of the world.  Some of
the more potent snakes may protect their territory as well as their
bodies.)

If you do unexpectedly confront a snake, stay calm, back away and 
do nothing to threaten it.  (This assumes of course that the
surprise didn't cause you to jump well beyond the snake's reach.
It's amazing what the human body can do in such circumstances.)

Don't run around barefoot in snake country, especially after dark. During
warm weather snakes will be most active at night and will defend
themselves if stepped on or if you walk too close and they sense danger. 
MFM lists going barefoot and gathering firewood after dark as two common
activities leading to snakebite.  Going barefoot not only exposes your
feet, it also makes your footsteps quieter so you are less likely to be
felt.  You could invest in a pair of snakeproof boots but any high top
leather boot is probably adequate.  Long pants will also help since the
snake has difficulty biting through a fold of your clothing. 

Remember that snakes like to hide under rocks, logs, and brush to protect
themselves from sun or cold.  Be very careful in snake country about
moving such objects or reaching into anywhere a snake might hide.  A snake
might well perceive your actions as aggressive and defend itself.  There
may be more than one snake in the same place and, taken by surprise, they
may strike without warning.  Furthermore snakes will be more likely to
bite your unprotected hand rather than a leg or foot protected by
clothing.  Remember, according to Curry, 74.4% of bites are to the upper
extremities. 

Rock climbers should be careful in snake country.  Snakes like to sun
themselves on ledges and it can be a real eye-opener to poke your head up
and stare one in the eyes.  And while you won't find them in the middle of
a 5.12 face you may find them in cracks and on ledges.  Remember, the
mice and rats which inhabit many cliff areas mean food to a snake and so
attract them. Small rock outcrops scattered around on foothills are prime 
snake territory, so be particularly careful when you go bouldering.

Be careful entering old buildings such as mining cabins.  They make
nice homes for snakes.

Obviously you should not handle or tease poisonous snakes.  Less 
obvious is the danger of handling them when they are dead.  A reflex
strike from a dead snake can be just as dangerous as a bite by a
live one.  This warning also applies to detached heads of dead snakes.

The degree of protection afforded by responsible behavior and protective 
clothing (boots, long pants) is remarkable. Iserson in JAMA reported on 
the incidence of snakebite in three groups of experienced outdoor 
workers. Members of the Southern Arizona Rescue Association worked 
115,000 person-hours in the field without a snakebite. The personnel at 
the La Selva Biological Station in Costa Rica (habitat of the fer de 
lance, a venomous crotalid) worked for 350,000 person-hours in the field 
without a bite. The graduate students at the Organization for Tropical 
Studies, also in Costa Rica, worked 660,000 person-hours in the field 
with only one bite.

Russell has something to say about this as well, "Few bites occur in 
backpackers, serious hunters, or fishermen...In the past 20 years, there 
has been only one backpacker in the Sierras of California, who I know of, 
who was bitten by a rattlesnake, and this happened when he was changing a 
tire at the end of his hike."

ENVENOMATION

In the article -When a snake strikes- ( Emergency Medicine, 1990,
22:21-43.), Russell states,

"25% of all pit viper bites do not result in envenomation and another 15%
are so trivial, they require only local cleansing and tetanus
prophylaxis."

Kurecki and Brownlee report that,

"Coral snakes lack retractable fangs. Instead they rely on fixed 
retroverted teeth to gnaw into the flesh of their prey. They must 
penetrate the skin long enough for their venom to be deposited around 
their teeth and into the wound. This envenomation mechanism is much less 
efficient than that of pit vipers; consequently, 50 percent of coral 
snakebites are dry."

The severity of the reaction to a snakebite depends on the degree of 
envenomation. Downey, Omer and Moneim describe a system whereby,

"grade 0 means there is no envenomation and indicates swelling and
erythema [redness] around the fang marks of <2.5 cm, grade 1 indicates
swelling and erythema of 2.5 to 15 cm but no systemic signs, grade 2
indicates swelling and erythema of 15 to 40 cm with mild systemic signs,
grade 3 indicates swelling and erythema of >40 cm with systemic signs, and
grade 4 indicates severe systemic signs including coma and shock." 

In their series of 36 patients, there were no grade 0 bites, five grade 
1 bites, 27 grade 2 bites, three grade 3 bites, and no grade 4 bites. 
So, this study suggests that most victims of snakebite will have a 
moderate local reaction with mild systemic signs. Life-threatening 
consequences such as shock are unlikely.  

SIGNS AND SYMPTOMS

Gold and Wingert describe the signs and symptoms associated with an
envenomated snakebite:

  "Panic is the most common reaction to a snakebite. As a result, the
victim may become emotionally unstable with thoughts of imminent death, or
conversely, the victim may enter a state of extreme lethargy and
withdrawal. Fear may cause such symptoms as nausea, vomiting, diarrhea,
dizziness, fainting, tachycardia [rapid hert rate], and cold, clammy skin. 
It is important that autonomic [flight or fight] reactions not be mistaken
for systemic symptoms and signs resulting from a bite. Such an error could
lead to unwarranted treatment.  The primary local symptoms and signs of
most pit viper envenomations are fang punctures, pain, edema [swelling],
and erythema [redness] or ecchymoses [bruising] of the bite site and
adjacent tissues. 
   There may be one or more puncture wounds, depending on the number of 
fangs the snake had, the accuracy of the strike, and the number of 
strikes inflicted. Superficial lacerations produced by fangs do not 
usually result in envenomation, because the discharge orifice of the fang 
lies slightly proximal to the tip. Teeth marks, other than fang 
punctures, may or may not be present. 
   There may be moderate pain in or around the local bite site in about
90% of pit viper envenomations. Exceptions are the bites from the Mojave
rattlesnake and the speckled rattlesnake, which cause little or no pain. 
...The pain, which had been described as sharp and burning in character,
usually develops within 5 minutes after inoculation [injection] of the
venom. 
   Edema and erythema or ecchymoses are characteristic of pit viper
envenomation and usually occur within 30 minutes of the bite, evolving
both proximally and distally as the venom spreads. If edema and erythema
have not manifested within 8 hours after a snakebite, it is generally safe
to assume that the patient has not been envenomated. Frequently, there are
signs of lymphangitis [inflammation of the lymphatic system] with tender
regional lymphadenopathy [disease of the lymph nodes].  Frequent systemic
manifestations after bites by eastern, timber, and western diamondback
rattlesnakes are perioral parathesias extending to the face and scalp with
tingling of the fingertips and toes. According to Russell, the most
frequent diagnostic findings after bites by the Pacific rattlesnake are
complaints of a 'minty,' 'rubbery', or 'metallic' taste in the mouth and
'tingling of the lips.' ...Skeletal muscle fasciculations [tics, spasms]
in the bitten area, face, neck, and back may occasionally become
generalized." 

Russell describes the effects of coral snake envenomation,

"The bite is usually associated with some pain, although it may be minor
and transitory in nature. Swelling is either absent or very minor. 
Parathesia [abnormal sensation] is sometimes noted around the bitten area,
and some weakness of the part may become evident within several hours of
the poisoning. The patient may complain of drowsiness, apprehension, and
weakness. Muscular incoordination may develop, and muscle fasciculations
[tics, spasms] and tremor of the tongue may be seen. Increased salivation
and difficulties in swallowing and phonation [speech pronunciation], as
well as visual disturbances, respiratory distress and failure, a bulbar
[brainstem] type of paralysis, convulsions, and shock may develop." 


FIELD TREATMENT

Now, what about treatment?  What do you do if you or a member of your
party becomes one of the unfortunate few to actually get bitten? 

The first thing is to remain calm. Remember, snakebite is not usually
deadly in spite of all the hype about it. Even without treatment you will
almost certainly recover. If you can identify the snake do so.  If it is
dead, take it with you to the hospital in a safe container to be sure of
getting the right antivenin.  Do not risk more bites in order to
kill it.  Remember the first rule of rescue: Do not create any more
victims or risk further injury to the current victim. 

Trained first aiders base their treatment of patients on a protocol: a 
simplified set of procedures. We describe below two different protocols 
for the treatment of snakebite.

 A Wilderness Protocol

The following treatment protocol is provided by Jeff Isaac and Peter Goth
in The Outward Bound Wilderness First Aid Handbook, Lyons and Burford,
1991. This same protocol is taught to Wilderness First Responders and 
Wilderness Emergency Medical Technicians certified by the National 
Association for Search and Rescue: 

"Transport the patient as quickly as possible to antivenin (antidote).
Although local discomfort may be severe, systemic signs and symptoms may
be delayed for two to six hours following the bite. Walking your patient
out is reasonably safe unless severe signs and symptoms occur. It is also
significantly faster than trying a carry. Splint the affected part if
possible. 
     
Expect swelling. Remove constricting items such as rings, bracelets, and
clothing from the bitten extremity. 

Do not delay. Immediately following the bite of a snake thought to be
poisonous, evacuation should be started. It can always be slowed down or
cancelled if it becomes obvious that envenomation did not occur, or the
snake is not poisonous. 
     
Most medical experts agree that traditional field treatments such as
tourniquets, pressure dressing, ice packs, and "cut and suck" snakebite
kits are generally ineffective and are possibly dangerous. Poisonous
snakebite is one of those conditions that you cannot treat in the field.
Don't waste valuable time trying." 

Boy, this is an awfully simple protocol! Doesn't seem to leave much for 
the first aider with an anxious desire to do something to occupy 
himself with. Well, at least they suggest you could make a nice splint.

Actually, a first responder, EMT, or other trained person would know that
there would be a number of other steps to field treatment that were not
explicitly stated in this protocol. He might want to evaluate the
patient's ABC's, take a history, record the time and events associated
with the bite, thoroughly evaluate and document the chief complaint,
conduct a physical exam, develop a plan for treatment and evacuation, and
begin recording a regular series of vitals. He would also record all
changes in signs and symptoms with the time that they occurred. None of
these activities, however, would be allowed to interfere with moving the
patient to definitive care (antivenin). Folks with a lesser set of skills
would want to do what they could. 

As part of the history, the first aider should ask whether the patient has
(a) asthma, hay fever, hives, or other allergies, (b) allergic reactions
upon exposure to horses, or (c) prior injections of horse serum. The two
antivenins in use in North America are both raised in horses, and patients
with allergies to horses or horse serum can exhibit adverse reactions (see
the discussion of hospital care below). The first aider should also ask
whether the patient has been bitten by venomous snakes in the past, and,
if so, whether he received antivenin and what the reaction to it was. 
Finally he should inquire when the patient last received a tetanus
booster. 

Don't forget to wear rubber gloves when handling patients, for your 
safety and theirs. Playtex dishwashing gloves are a good choice for 
wilderness use, but disposable latex surgeon's gloves work fine too. If 
it is necessary to assist a patient's respirations, use a pocket mask.

If the group is sufficiently large, it might be best to send two runners 
ahead to summon aid. At the very least, it would be nice to have an 
ambulance waiting at the trailhead. There is a maxim in wilderness 
first aid: move the patient to treatment, and move treatment to the 
patient. The best evacuation strategies will cause both of these things to 
happen simultaneously.

If it is going to be more than 1 hour to hospital treatment, you may choose
to rinse and disinfect the wound. More on how to do this follows below. 

An Urban Protocol

The following more elaborate protocol is taken from the -Emergency Medical 
Technician 1A Protocols- for Fresno County in California. The protocol is 
designed for EMS personnel in an urban setting:

"I. Priorities

A. Assessment. Vital signs, site of wound, measure the circumference of 
the extremity, mark and record, note extent of swelling and record time. 

B. Keep patient quiet and reassure. 

If snake is available and dead, place in a secure container and bring to 
the emergency department. Use caution. Do not engage in a search for the 
snake. 

C. Code 3 transport [lights, siren] is indicated for patients in shock, 
uncontrolled bleeding or with concurrent severe injuries.

Code 2 [normal driving, no lights, siren] transport for patients with stable 
vital signs without immediate life threat.

[Folks that choose to transport a snakebite victim by personal auto to a
hospital should note these instructions. Life-threatening systemic
reactions are rare with snakebite, so safe driving within the speed limit
is the way to go. Given the amount of panic associated with snakebite, it 
might be best to allow an ambulance transport the patient, and thereby 
reduce the risk of an automobile accident]

II. Treatment

A. Oxygen 6 L/min by nasal cannula. [If not trained in O2 delivery, then 
don't do this, RP]

B. Apply elastic bandage 2-5 inches proximal to the bite if transport >10 
minutes. Do not apply to hand or foot. No other tourniquet should be 
used. This should be applied to a tightness which allows you to slip one 
finger underneath.

C. Immobilize affected extremity at or slightly below the level of the 
heart. 

D. Keep patient at rest.

E. Mark area of swelling with pen line and record time.

III. Further Evaluation

A. If the snake was an exotic pet or zoo animal (e.g. coral snake, cobra, 
krait), neurotoxic symptoms may precede local reactions. Observe for 
mental status change, respiratory depression, convulsions, or paralysis.

B. Do not allow any person to apply ice or cooling. Do not allow incision 
of the wound.

C. The best course of action following envenomation is rapid transport to 
the emergency department where intravenous antivenin can be administered.

D. Reassure patient. Mortality from snakebite is rare, particularly in 
young, healthy patients."


Once again, this protocol does not mention all the neat things that
trained EMS folks do for every patient. See the discussion following the 
wilderness protocol above.

So two quite different approaches. One, designed for the wilderness, 
allows the patient to walk toward treatment. The other, designed for an 
urban setting with ready access to the EMS system, had the patient remain 
at rest, with the wound immobilized at or below the level of the heart.

Which to follow? It is up to you to decide. But, a few comments that may 
help are listed below.


FIELD TREATMENT: AREAS OF DISAGREEMENT

Keep the Patient Immobilized, Wound at or below Level of Heart

We described one field treatment procedure, designed for the wilderness,
that allows the patient to walk toward treatment. The other, designed for
an urban setting with ready access to the EMS system, required the patient
remain at rest, with the wound immobilized at or below the level of the
heart. 

In the urban setting, nothing is to be lost by the "keep patient at rest"
approach. But in deciding what to do where help is an hour or more away,
here are a few thoughts: (1) Antivenin is the definitive therapy for
snakebite. Kurecki and Brownlee say,

"Remember, based on the current literature, the single most effective 
course of action following a pit viper bite is rapid transport to an 
emergency department because the intravenous administration of antivenin 
remains the definitive and only therapy of proven value. The best first 
aid is a set of car keys."

(2) The systemic reactions to snakebite are often delayed, giving a 
window that can be used to have the patient aid in his own rescue. Here 
is what Gold and Wingert say,

"Several hours usually elapse after the bite before the severe toxic 
effects of the venom ensue. According to Parrish [Am J Med Sci, 1963, 
245:129-41.], of 138 people who died from snakebites over a 10-year 
period, only 4% died within 1 hour and only 17% died within 6 hours. The 
majority (64%) died 6 to 48 hours after the bite. Victims of snakebites 
who received medical attention within the first 2 hours after being 
bitten have an excellent chance of survival."
 
(3) There is little evidence in the literature that activity can worsen
the outcome associated with snakebite (Keith Conover, personal
communication). (4) There is little evidence in the literature that
keeping the bitten extremity at or below the level of the heart has an
effect on the outcome due to snakebite (Keith Conover, personal
communication). (5) Evacuating a patient from the wilderness who is kept
at rest necessitates a BIG rescue effort. It poses a potential risk to the
rescuers themselves. (6) Waiting for a big rescue to be organized and
executed could delay getting the patient to antivenin. (7) There is a
tradition of self-rescue in mountaineering and other backcountry sports. 

Constriction Bands

Most authorities agree that a constriction band may be of benefit. Here 
is what Gold and Wingert say,

"If the anticipated delay in treatment is several hours and evaluation is 
done within 5 minutes of the snakebite, a constriction band may be 
applied about 5 cm above the bite or just proximal to the closest joint. 
The band should be tight enough to occlude lymphatic flow, yet loose 
enough so as not to impede arterial or venous circulation. The pulses 
distal to the bite should be palpated frequently to ascertain flow, and 
the band should be loosened, but not removed, if too tight."

A constriction band is not a tourniquet!! If you are not confident
that you can assess vascular function in an extremity, then you should not
carry out this procedure. Swelling will cause this band to become 
tighter. It is going to require constant monitoring, and the band will 
have to be loosened as necessary. Forget to monitor or fail to properly 
assess vascular function, and you could cause permanent disability.
Do not apply a constriction band directly to a  digit, foot, or hand.

Wound Cleaning

The two protocols listed in the section on treatment do not mention 
cleaning the bite wound. However, if it is going to be an hour or two to 
get the patient to the hospital, you might consider cleaning the wound. 
Here is what Wilkinson in MFM says, 

"The skin should be washed and swabbed with an antiseptic. (Such obvious 
measures to reduce contamination are frequently neglected, resulting in 
infections which are responsible for a large part of the residual damage 
from snake bites. The bacteria that cause tetanus and gas gangrene have 
both been isolated from the mouths of poisonous snakes.)"

Providone-iodine solution (10% in water, trade name Betadine) diluted 
1:10 in clean water to make a 1% final concentration makes a fine 
antiseptic solution.

Extractor Devices

The Sawyer's Extractor is a spring-loaded piston that attaches to any of 
several sizes of cylindrical vacuum chambers. Although neither of the two 
treatment protocols above suggest its use, many authorities suggest it 
might be useful. Gold and Wingert state, 

"A number of field studies have shown that a Sawyer's Extractor (Sawyer's 
Products, Safety Harbor, Fla), which provides about one atmosphere of 
negative pressure, is effective in extracting venom from the bite site, 
provided it is applied within the first 5 minutes after the victim is 
bitten. Suction should then be continued during the first 30 to 60 
minutes after a bite."

FIELD TREATMENT: 'THERAPIES' TO AVOID

Incisions

Don't use them. Gold and Wingert say,

"The use of ice, tourniquets, incision and suction, and electric shock
therapy as part of emergency field therapy should be strictly
discouraged."

Similarly, Kurecki and Brownlee say,

"The complications of incision and suction, especially in the hands of 
the untrained person who does not know the anatomy of the body, include 
damage to underlying structures, vascular compromise to the extremity, and 
infection. The blade in a snakebite kit is of sufficient size and quality 
to damage underlying blood vessels, nerves, tendons, and muscles. It has 
never been shown in a clinical trial that incision and suction improves 
motality, although morbidity through improper incision is increased."

If you have one of those little green snakebite kits, you might as well 
discard it. The little sharp knives are dangerous to use, and the suction 
developed by the little rubber cups is insufficient to be of benefit. See 
the discussion of extractor devices above. While you are discarding 
dangerous implements from your first aid kit, you might as well throw out 
those ammonia inhalants and salt tablets too.

Oral Suction

Do not try to suck venom from a wound by mouth. You might cause a severe
infection in the wound due to bacteria from your mouth. And, you do not
want to take a risk of absorbing venom through a cut, or a sore, or bleeding
gums. Finally, given the risk of blood-borne pathogens such as hepatitis
and AIDS, putting your mouth to a wound on another person is an unwise
practice.

It is worth repeating here: use gloves when handling patients,
particularly if they have a wound. Use a pocket mask if you assist
respirations. 

Tourniquets

Don't use them. Gold and Wingert say,

"The use of ice, tourniquets, incision and suction, and electric shock 
therapy as part of emergency field therapy should be strictly 
discouraged. Dart [Dart, R. and Russell, F.E.-Animal Poisoning-. in 
Principles of Critical Care. Hall, Schmidt and Wood (eds). New York, 
McGraw-Hill, 1992, 2163-71.] studied 94 snakebite victims at University 
of Arizona. Of 18 patients who had used a tourniquet, problems developed 
in 8; 6 had tissue loss, and 2 had permanent disability resulting 
directly from the use of a tourniquet."

See the discussion above of constriction bands.

Compression Wraps

In North America, don't use them. For the same reasons as tourniquets. In 
Australia, the bites of the elapids they have there have a greater 
potential for fatal outcome. Physicians there have used compression wraps 
with success. Inquire about local procedures when you travel.

Electrical shock 

Don't use it. Electrical shock was tried experimentally for a time, and 
several portable devices were developed. These still turn up in use from 
time to time at rattlesnake roundups and the like. No research data ever 
emerged that supported the use of electric shock.

Ice or Cold Packs

Don't use them. Here is what James Wilkerson says in Medicine for 
Mountaineering (3rd Ed):

"Packing an extremity bitten by a poisonous snake in ice or snow probably
would not be possible in most wilderness situations because snakes do not
inhabit areas where ice and snow are available. However, such therapy for
poisonous snake bite has been recommended in the past. The basis of such
therapy was the assumption that the active components of snake venom were
enzymes, the activity of which would be reduced by cooling. However,
subsequent studies have determined that most of the toxins in snake venom
are peptides, which are not inactivated by cooling. Additionally, since
snakes are cold blooded animals, their enzymes remain active at
temperatures at which a warm blooded human's defenses are immobilized.
Furthermore, some enzymes are driven deeper into warmer tissues by cooling
the skin. 

Few physicians advocate local cold therapy; even fewer would deny that
its use outside the hospital as a technique for emergency care has
caused the loss of many limbs."

Cold causes increased local tissue destruction when applied to
North American pit viper bites.  See the following references:

Sullivan JB Jr, Wingert WA.  Reptile Bites.  in Auerbach PS, Geehr
EC, Ed Management of wilderness and environmental emergencies.  2nd
ed.  St.  Louis:  C.V.  Mosby Co., 1989:479-511.

Gill KA Jr.  The evaluation of cryotherapy in the treatment of snake
envenomation.  So Med J 1968;63:552-6.

Durand LS, Rodeheaver GT, Edlich RF.  Poisoning by pit vipers.
W Va Med J 1982;78(7):162-7.

HOSPITAL CARE

The definitive care in the hospital will be i.v. administration of 
antivenin. The number of vials of antivenin administered will depend on 
the severity of the envenomation. Snakebite patients who were not 
envenomated or who were bitten by a copperhead may not receive antivenin.

There are two antivenins in common use in the United States. Both are 
manufactured by Wyeth-Ayerst Laboratories and are created by injecting 
venom into horses, and then collecting the resulting immune serum. 

Antivenin (Crotalidae) Polyvalent is developed by injecting a mixture of 
the venoms of eastern diamondback, western diamondback, cascabel 
(tropical rattlesnake), and fer-de-lance into horses. This antivenin is 
used for treating the effects of bites from crotalids native to North, 
Central, and South America, as well as Japan and Korea.

Antivenin (Micrurus fulvius) is developed by injecting the venom of the 
eastern coral snake into horses. It is used for treating the bites of 
both eastern and Arizona coral snakes. 

There is a potential for a dangerous reaction to antivenin in patients 
who have an allergy to horses or horse serum. For this reason antivenin 
is only administered in a hospital, and the physician makes every effort 
to rule out allergy before he administers the antivenin. The adverse 
consequences of antivenin administration in patients allergic to horses 
include shock, anaphylaxis, and serum sickness.

If your physician desires more information on the two antivenins used for
the treatment of North American snakebites, he can contact the manufacturer:

Professional Services
Wyeth-Ayerst Laboratories
PO Box 8299
Philadelphia, PA 19101
(610) 688-4400, or
(800) 950-5099

Also while in the hospital, the bite wound will be cleaned, and the 
patient will subjected a battery of laboratory tests. Any of a variety of 
drugs and i.v. fluids may be administered including D5W, saline, plasma, 
blood products, antiphylaxis agents, sedatives, analgesics, and antibiotics.

The patient may receive a tetanus booster. Continuing wound care will 
include cleansing, and may include surgical treatment of the wound area. 
If movement or strength of an extremity is compromised, patients may 
receive physical therapy.

COMPLICATIONS

Downey, Omer and Moneim reported 68 complications in their study group of
36 snakebite victims. The most frequent was compartment syndrome
(increased pressure within a closed body compartment, interfering with
function), which occurred in 25 patients. All 25 received surgical
intervention (fasciotomy). The breakdown of all complications was as follows:

Compartment syndrome             25
Carpal tunnel syndrome            1
Reduced range of motion           9
Reduced sensation                 4
Thrombosed digital artery         1
Wound infection                   4
Tendon necrosis                   1
Digit amputation                  1
Abnormal coagulation studies      7
Thrombocytopenia                  4
Postoperative anemia              4
Serum sickness                    4
Hypotension                       3
Pleural effusion                  1

The length of hospital stay ranged from 1 to 31 days; the median was 5
days. 

GLOSSARY

The definitions below are simplified; you would find more subtle and 
complex definitions in dictionaries of biology or medicine.

anemia     Abnormally low number of red blood cells in the blood.

antivenin     Antiserum used to treat the victims of snakebite. 
  Manufactured by hyperimmunizing horses with snake venom.

autonomic reaction     Flight or fight reaction.

bulbar      Pertaining to the brainstem. Bulbar functions include the
  maintenance of heart rate and breathing. 

carpal tunnel syndrome

coagulation     Clotting of blood.

compartment syndrome     The effect of swelling within a closed body space.

crepuscular     Active at twilight.

crotalid      A member of the snake subfamily Crotalinae, the pit vipers.

distal     Toward the periphery of the body and away from the central 
  axis. Opposite: proximal.

ecchymoses     Bruising.

edema     Swelling

elapid     A member of the snake family Elapidae, which includes the 
  coral snakes and other venomous snakes with immovable hollow fangs at the 
  front of the mouth.

envenomation     Injection of venom.

erythema     Redness.

fasciculations     Tics or spasms.

hemolytic toxin    Poison which attacks the blood.

hybrid    The offspring deriving from the mating of members of two 
  different species.

hypotension     Low blood pressure.

inoculation     Injection.

lymphadenopathy    Disease of the lymph nodes.

lymphangitis     Inflammation of the lymph nodes.

nasal cannula     A hoop of plactic tubing with two open nozzles which 
  insert into the nostrils.  Used for the delivery of oxygen.

necrosis      Death of tissue.

neurotoxin     Poison which attacks nervous tissue.

parathesias     Abnormal sensations.

perioral     Around the mouth.

phonation     Speech pronunciation.

pleural effusion     Escape of fluid into the space outside the lungs and 
  inside the chest wall.

prophylaxis     Prevention.

protocol     Procedure or rules of action.

proximal     In the direction of the central axis of the body. Opposite: 
  Distal.

serum     The watery component of blood.

serum sickness     An allergic reaction after administration of a foreign 
  serum.

shock     The life-threatening systemic reaction to inadequate perfusion 
  of the tissue with oxygenated blood. Not the same as an autonomic reaction.

tachycardia     Fast heart rate.

tetanus     An infectious disease due to the toxin of tetanus 
  bacteria growing at the site of an injury.          

thombosed     Containing a blood clot (a thrombosis).

thrombocytopenia     Abnormal decrease in the number of blood platelets.

toxin    A poison. Syn: venom.

venom     A poisonous secretion of certain plants and animals. Syn: toxin.


DISCLAIMER

This FAQ does not constitute professional medical advice. It is merely a 
compilation of information available in the literature. If you need 
professional medical advice on snakebite or any other topic, consult your 
physician.

-----------------------------------------------------------
(Written by Hal Lillywhite.  Last update:  14 February 1994)
(Revised by Richard Penny.   Last update:     9 August 1995)


>From "Last Chance to See"

	"Oh, you don't have to worry about identifying Tasmanian
	snakes. They're all poisonous."
...
	  "So what do we do if we get bitten by something deadly, then?" I
	asked.
	  He blinked at me as if I were stupid
	  'Well what do you think you do?' he said.  'You die of course.
	That's what deadly means.'
	  'But what about cutting open the wound and sucking out the poison?'
	I asked.
	  'Rather you than me,'  he said.  'I wouldn't want a mouthful of
	poison.  All those blood vessels beneath the tongue are very close
	to the surface so the poison goes straight into the bloodstream.
	That's assuming you get much of the poison out, which you probably
	couldn't.  And in a place like Komodo it means you'd probably
	quickly have a seriously infected wound to contend with as well
	as a leg full of poison.  Septicaemia, gangrene, you name it.
	It'll kill you.'
	  'What about a tourniquet?'
	  'Fine if you don't mind having your leg off afterwards.  You'd have
	to because it would be dead.  And if you can find anyone in that part
	of Indonesia who you'd trust to take your leg off then you are a
	braver man than me.  No, I'll tell you: the only thing you can do is
	apply a pressure bandage direct to the wound and wrap up the whole
	leg up tightly, but not too tightly.  Slow the blood flow but don't
	cut it off or you'll lose the leg.  Keep the leg or whatever bit
	of you it is you've been bitten in, lower than your heart and your
	head.  Keep very, very still, breathe slowly and get to a doctor
	immediately.  If you're in Komodo that mean a couple of days,
	by which time you'll be well dead.
	  'The only answer, and I mean this quite seriously, is don't get
	bitten.  There is no reason why you should. ... No, the things you
	really need to worry about are the marine creatures.'
	  'What?'
	  'Scorpion fish, stonefish, sea snakes.  Much more poisonous than
	anything on land.  Get stung by a stone fish and the pain alone can
	kill you.  People drown themselves just to stop the pain.'
        ...
	  'Is there anything you do like?'
	  'Hydroponics.'
	  'No I mean are there any venomous creature you're particularly
	fond of?'
	  He looked out of the window for a moment.
	  'There was,' he said, 'but she left me.'
	--Douglas Adams, Chapter 2 "Here Be Chickens," in Last Chance to See

An older copy of this file (check last modified dates) can be found at:
ftp: sunSITE.unc.edu:
pub/academic/agriculture/sustainable_agriculture/health-safety-FAQs


MEDICINE FOR MOUNTAINEERING. Forth Edition.
Edited by James. A. Wilkerson. MD. The Mountaineers. ISBN:
0-89886-331-7


SPIDERS

Almost all spiders produce toxic venoms, but their fangs are too small
and weak to penetrate the skin, the venom is too weak, of the volume
of venom is too small to pose a significant threat for humans.  The
black widow (Latrodectus mactans) is the only spider found in the
United States that is capable of routinely producing serious illness
by its bite.  The "tarantula" native to the U.S. Southwest bites only
after extreme provocation.  Its weak and ineffective fangs can only
penetrate thin skin, such as that on the sides of the fingers; the
effects of the bite are no worse than an insect sting.
In other parts of the world are spiders that can cause severe, even
fatal poisoning in humans.  Other species of Latrodectus produce
effects similar to the black widow.  The bites of large, hairy
tarantulas found in areas such as Brazil or Peru can have similar
results.  The Sydney funnel web spider, reportedly limited in
distribution to the area within 100 miles of Sydney, Australia, is
capable of inflicting a bite that can be lethal for healthy young
adults.
Some spiders, such as the brown, or violin, spider (Loxoseeles
recluse) inflict bites that occasionally cause extensive damage at the
site, but usually have less severe generalized effects.  The jumping
spider (Phidippus) is the most common biting spider in the United
States.  Bites by this spider, trapdoor spiders, orbweavers, and
spiders of the Chiracanthium species, such as the garden spider,
commonly produce local reactions that ulcerate and less often produce
systemic symptoms.  However, individuals with these bites almost never
require hospitalization.  Spiders usually cling to the site of the
bite. (If the spider can not be found, some other arachnid, such as a
bedbug, should be suspected.) Anyone who has been bitten should take
the spider to be identified.
Rarely, an individual may be bitten repeatedly by a relatively
harmless spider or insect and develop an allergy to the toxin produced
by that species.  Subsequent bites can produce severe, even fatal
allergic reactions.  Fortunately such events are rare.  The treatment
for such reactions is identical to the treatment for allergic
reactions to Insect stings.



BLACK WIDOW SPIDER BITES

The female black widow typically is coal black and has a prominent,
spherical abdomen that may be as large as one-half inch (1.25 cm) in
diameter.  This appearance is so distinctive that finding the
characteristic markings on the undersurface of the abdomen is rarely
necessary.  The typical markings consist of red or orange figures that
usually resemble an hourglass, but may be round, broken into two
figures, or have some other configuration.  Markings of the same color
but in varying patterns are sometimes present on the back, although
only the undersurface markings are considered characteristic.  In some
southwestern states black widow spiders have irregular white patches
on their abdomens.  Different species of Latrodectus in other
countries have a similar appearance. (fbe mate is smaller, has a brown
color, and is harmless.)
The black widow weaves a coarse, crudely constructed web in dark
corners, both indoors and out.  Almost half the black widow bites
reported in the medical literature in the first four decades of this
century were inflicted on the male genitalia by spiders On the
underside of outdoor toilet seats.  However, this spider is timid and
would rather run than attack an intruder.
Thirty to forty years ago five to ten deaths a year resulted from
black widow spider bites, although they were limited almost entirely
to small children or elderly individuals in poor health.  Recognition
and treatment of such bites has improved so much that deaths are rare
within the United States. (Bites in children weighing thirty pounds or
less would still have a mortality of about fifty percent if
untreated.) In healthy adults, black widow spider bites cause painful
muscle spasms and prostration for two to four days, but complete
recovery essentially always follows.  Antivenin treatment is not
recommended for adults.
The bite may feel like a pin prick, may produce a mild burning, or may
not be noticed at all.  Small puncture wounds, slight redness, or no
visible marks may be found at the site of the bite.  Within about
fifteen minutes painful muscle cramps develop at the point of the bite
and rapidly spread to involve the entire body.  The characteristic
pattern of spread is by continuity.  From a bite on the forearm the
cramps would spread to the upper arm, to the shoulder, and over the
chest to involve the rest of the body, including the legs.  The
abdominal muscles are characteristically rigid and hard, although the
abdomen is not tender.  Weakness and tremors are also present.
A typical subject is anxious and restless.  A feeble pulse and cold,
clammy skin suggest shock; labored breathing, slurred speech, impaired
coordination, mild stupor, and rare convulsions (in children) suggest
disease involving the brain, Bitten individuals are often covered with
perspiration; dizziness, nausea, and vomiting are common.  If the
spider or its bite have not been observed, the signs and symptoms may
lead to an erroneous diagnosis of an acute abdominal emergency.
Symptoms typically increase in severity for several hours,
occasionally as long as twenty-four hours, and then gradually subside.
After two or three days essentially all symptoms disappear, although a
few minor residua may persist for weeks or months.
Treatment consists of efforts to relieve the painful muscle spasms and
antivenin for small children.  No treatment at all should be directed
to the site of the bite, with the possible exception of applying an
ice cube to relieve pain.  Incision and suction is damaging and
useless and should not be performed.
Essentially nothing can be done outside a hospital; small children
must be hospitalized.  Antivenin, produced in the United States by
Merck Sharp & Dohme, and the drugs to control spasms are rarely
available anywhere else.  The antivenin is prepared in horses and
should not be given to persons allergic to horse serum.  It is usually
not administered to healthy adults between the ages of sixteen and
sixty, and only to individuals of small body size with severe symptoms
who are twelve to fifteen years old.  Instructions with the vial of
antiserum should be followed.
Muscle spasms may be relieved by periodic injections of 10 cc of a ten
percent calcium gluconate solution or 10 cc of methocarbamol, but
these are rarely available outside a hospital.  A tranquilizer
(diazepam) may help relieve less severe muscle spasms; hot baths are
occasionally helpful.  Strong analgesics are helpful but rarely
provide complete pain relief.


BROWN SPIDER BITES

The brown, or violin, spider (Loxosceles recluse) more recently
labeled the "brown recluse spider," has received attention as the
cause of "necrotic arachnidism." Following the bite of this spider, a
blister appears, and is surrounded by an area of intense inflammation
about one-half inch (1.25 cm) in diameter.  Pain is mild at first but
may become quite severe within about eight hours.  Over the next ten
to fourteen days the blister ruptures and the involved skin turns dark
brown or black.  Eventually the dead, black tissue drops away, leaving
a crater that heals with scarring.
A few individuals have large skin losses that require grafts to cover
the defect.  Some children have lost considerable portions of the
face.  Such events have attracted great notoriety for this spider,
even though much smaller wounds are far more typical.  Bites are
attributed to Loxosceles recluse (incorrectly) well outside of its
habitat, which is limited to the southeastern and south-central
portion of the United States and ends at the Texas-New Mexico border.
Generalized symptoms that may appear within thirty-six hours of the
bite include chills and fever, nausea and vomiting, joint pain, and a
skin rash or hives.  With severe reactions, red blood cells are broken
down (hemolysis) and platelets are destroyed (thrombocytopenia), which
can result in a significant anemia and bleeding tendency.  Rare
fatalities have occurred, mostly in children.
Essentially nothing can be done for such bites in a wilderness
situation unless appropriate injectable medications are carried along.
If the person can be hospitalized within less than eight hours, the
site of the bite can be surgically excised.  Such therapy should be
reserved for bites from spiders clearly identifiable as L. recluse, so
the spider must be captured (intact if possible) and brought to the
hospital to be identified.  After eight hours the area involved may be
too large to be excised.  Corticosteroids may also be administered.
One recommended program is 4 mg of dexamethasone, administered
intramuscularly every six hours until the reaction starts to subside,
and then in tapered doses.  Others include injection of hydrocortisone
beneath the bite and the administration of dapsone.  Nothing is very
satisfactory.

SCORPION STINGS

Scorpions are found throughout most of the United States, but the
species lethal for man, Centruroides, are limited to Arizona, New
Mexico, Texas, southern California, and northern Mexico.  In these
areas scorpions are a significant problem.  Sixty-nine deaths resulted
from scorpion stings in Arizona between 1929 and 1954.  During the
same period, only twenty deaths resulted from poisonous snake bites.
With improved medical management of the complications of scorpion
stings, no deaths have occurred in Arizona for twenty years.
Scorpions are eight-legged arachnids that range in length from three
to eight inches (7.5 to 20 cm) and have a rather plump body, thin
tail, and large pinchers.  They are found in dry climates under rocks
and logs, buried in the sand, in accumulations of lumber, bricks, or
brush, and in the attics, walls, or understructures of houses or
deserted buildings, The problems with scorpions in Arizona are clearly
related to their tendency to live in the vicinity of human habitation
where children are frequently playing.
Stings can be avoided by exercising care when picking up stones, logs,
or similar objects under which scorpions hide during the day.  Since
scorpions are nocturnal, walking barefoot after dark is inadvisable.
Shoes and clothing should be shaken vigorously before dressing in the
morning, particularly when camping outdoors.
The lethal species of scorpions are often found under loose bark or
around old tree stumps.  They have a yellow to greenish yellow color
and can be distinguished from other species by a small, knoblike
projection at the base of their stingers.  Adults measure three inches
(7.5 cm) in length and three-eighths inch (I cm) in width.  One
subspecies has two irregular dark stripes down its back.
The sting of a nonlethal scorpion has been described as similar to
that of a wasp or hornet, although usually somewhat more severe, and
should be treated in an identical manner. (Scorpion venom is not
identical to insect venom, and individuals allergic to insect stings
usually are not allergic to scorpion stings.) Lethal scorpion stings
are more painful, but fatalities have been limited almost entirely to
small children.
Initially the sting of a scorpion of one of the lethal species
produces only a pricking sensation and may not be noticed.  Nothing
can be seen at the site of the sting. (Swelling and red or purple
discoloration are indications that the sting has been inflicted by a
nonlethal species.) Pain follows in five to sixty minutes and may be
quite severe.  The sting site is quite sensitive to touch and is the
last part of the body to recover.  Tapping the site produces a painful
tingling or burning sensation that travels up the extremity toward the
body. (Apparently stings by other species of scorpions can
occasionally produce a similar sensation.) Sensitivity may persistas
long as ten days, although other symptoms usually disappear
within ten hours.
Individuals who have been stung typically are extremely restless and
jittery.  Young children writhe, jerk, or flail about in a bizarre
manner that suggests a convulsion.  Their movements are completely
involuntary.  However, in spite of their constantly moving bodies, the
children can talk.  Although they appear to be writhing in pain, they
usually state that they do not hurt.  Convulsions have been described,
but the true nature of these events is questionable.  Visual
disturbances such as roving eye movements or a fluttering type of
movement known as nystagmus are common.  Occasionally a child
complains that he can not see, but nothing abnormal can be found when
examining his eyes, and sight returns spontaneously in a few minutes.
Children under six years of age may develop respiratory problems such
as wheezing and stridor, and a few may need assisted respiration.
Persons who have been stung typically have an elevated blood pressure,
which may be an important diagnostic sign since hypertension is rare
in children.  The blood pressure usually returns to normal within four
to six hours and becomes life-threatening only in infants.
Elderly individuals with preexisting health problems and small
children stung by one of the lethal scorpion species should be taken
to a hospital.  Only a medical facility of that sophistication has the
equipment and supplies necessary to monitor these individuals and deal
with any complications that may arise.  An ice cube applied to the
site of the sting may help reduce pain, but no other therapy is
possible outside a hospital.  In locations such as the Grand Canyon,
where prompt evacuation is not possible, diazepam can be given to
children for control of the involuntary movements.
Other countries have species of lethal scorpions much more deadly than
those in the Southwestern United States.  Mexico reportedly has had as
many as 76,000 scorpion stings resulting in 1,500 deaths in a single
year.  The stings of such scorpions must be treated with antivenin,
which is rarely obtainable outside a hospital, particularly by someone
who does not speak the country's language.  Death from the stings of
such scorpions is usually the result of sudden, very severe high blood
pressure.  Adrenergic blocking agents such as propranolol may be an
effective method for treating such stings and probably should be
carried by visitors to the countries where such lethal species of
scorpions exist.


//no more//

ALLERGIC REACTIONS TO INSECT STINGS

Between fifty and one hundred deaths result annually from allergic
reactions to Hymenoptera stings (bees, wasps, hornets, and fire ants)
in the United States, more than the deaths from rabies, poisonous
snakes, spiders, and scorpions combined.  Approximately one of every
two hundred people in the United States has experienced a severe
reaction to such stings.  Potentially fatal reactions can be prevented
or successfully treated in individuals known to have such allergies,
but many deaths still occur in persons whose allergic status had not
been previously recognized.  The problem of allergies and the severe,
potentially lethal allergic reactions known as "anaphylactic shock"
are discussed in Chapter Twenty, "Allergies."
An individual allergic to insect stings usually experiences milder
allergic reactions before having a potentially fatal reaction.  Two
types of nonlethal reactions occur: local reactions and systemic
reactions.
Local reactions are characterized b severe swelling limited to the
limb or portion of the limb that is the site of the insect sting.
Almost all insect stings are associated with some swelling, but the
area of swelling is usually three inches (7.5 cm) or less in diameter.
With severe local reactions, a major portion of an extremity, such as
the entire forearm, is swollen, and may be painful, associated with
itching, or mildly discolored.
Systemic reactions occur in areas of the body some distance from the
site of the Sting.  Most typical are hives, which may be scattered
over much of the body.  Generalized itching or reddening of the skin
may also occur.  Persons with more severe reactions may have
hypotension (low blood pressure) and difficulty breathing. (Clearly,
the last two reactions could be fatal if severe.)
Investigators of insect hypersensitivity reactions have recommended
that individuals who have had a systemic reaction to an insect sting
undergo skin testing with Hymenoptera venoms. (If the results of skin
tests are inconclusive, more sophisticated measurement of
venom-specific IgE antibodies by the radioallergosorbent procedure can
be carried out.) About half of the people who have had a systemic
reaction and also have a positive skin test would be expected to have
a severe, possibly fatal reaction if stung again.  Desensitization
with purified insect venoms-not whole-body extracts-is recommend for
these individuals. (In one recent study of children who had
experienced an anaphylactic reaction following a sting, only nine
percent of subsequent accidental stings led to severe reactions.  None
of the reactions were more severe than the original reactions, which
led to the conclusion that immunotherapy was unnecessary for such
individuals.)
Desensitization can be a drawn-out, uncomfortable procedure but also
can be life-saving.  Starting with very small quantities, increasingly
larger amounts of the insect venoms are injected subcutaneously until
the allergic reaction is "neutralized." The individual is still
allergic to the Hymenoptera venoms, but the antibod'ble for producing
the allergic reactions are "used up" by the repeated les response I
injections of the material with which they react.  Generally, even
after successful desensitization, injections must be continued at
approximately monthly intervals for years or indefinitely.  If the
desensitization injections are stopped, the former allergic condition
often reappears.
Desensitization must be carried out under the close supervision of a
physician experienced with the procedure.  Severe, life-threatening
allergic reactions to the desensitization injections may occur, and a
physician must be on hand to deal with them.  However, a physician who
is standing by watching for a reaction can treat it effectively.
Allergic reactions to insect stings in a wilderness environment
without a physician in attendance are a far greater threat.
Desensitization, or even skin testing, is not recommended for
individuals who have large local reactions because these are rarely
followed by systemic reactions.  However, carrying epinephrine
(adrenaline) is recommended for individuals who have had either type
of reaction.
For individuals experiencing an anaphylactic reaction, 0.3 cc of a
1:1,000 solution of epinephrine should be injected subcutaneously as
soon as symptoms are detected.  Second (and sometimes third)
injections are often needed at intervals of twelve to fifteen minutes.



Rock climbers and some other wilderness users who have systemic
allergic reactions to insect stings have a unique risk of fatal
reactions because they are subject to stings in locations, such as
rock walls, where they can not be immediately treated by others and
only with difficulty by themselves.  Such persons should seriously
consider desensitization now that purified venom preparations, which
make that procedure so much more reliable, are available.  They also
must be prepared to treat an anaphylactic reaction at any time.


From: WWWbstr@aol.com
Date: Tue, 13 Aug 1996 18:18:59 -0400
Message-ID: <960813181859_455662310@emout15.mail.aol.com>
Subject: DW - Snakebite statistics

I just finished reading the DW on snakes; found it very useful but had a
minor quibble.  I hope I'm commenting on the current version - my newsreader
(AOL 3.0) won't let me open or download it (or the water filter / giardia DW)
because of size; I had to resort to the HTML version pointed to from the AT
homepage.

There was an excerpt from the article by Curry et al, studying 85 bites
treated at a single center.  A little further down:

> Remember, according to Curry, 74.4% of bites are to the upper extremities.

Three points:

1)  I don't think 85 samples justifies reporting to 0.1%.

2)  Curry notes that only 27% of the upper extremity bites were legitimate.
 Thus the proportion of _legitimate_ bites which are to upper extremities
drops to the general neighborhood of 20% (assuming that nobody made up a
story about firewood rather than admitting that he got himself bitten by
being stupid).

3)  There was no indication in the excerpt of how the treatment center was
selected.  If it is located in an area with, say, an unusually large number
of macho idiots who get drunk and pick up "pet" snakes, the data would
obviously be skewed.  Likewise, a center from an area with a lot of rock
climbers would probably show an unusually large number of legitimate upper
extremity bites.  IMHO, the study sheds interesting light on the subject but
one should avoid any statement which might seem to extrapolate its data to
the full range of snakebite (otherwise, an alternate conclusion would be:
 "snakes don't bite women" - that might make an entertaining thread...).

Anyway, thanks for distilling the wisdom; I just felt I had to comment on an
apparent misuse of statistics.

- Will Webster (on my way to get the OB 1st Aid Manual)



**FAQ: Venomous Critters **


An interesting summary on poisonous snakes, spiders, lizards, and 
scorpions, with up-to-date treatment.  Worth reading, and rather 
humorous besides.  Especially good for those moving to the southwest 
or southeast!

                                 Venom Nation

Vipers, spiders and scorpions.  A traveler's guide to our poisonous pals.

Within the United States there are five groups of dangerous venomous animals
that travelers might expect to encounter: pit vipers, coral snakes, scorpions,
spiders and lizards (two other groups - centipedes and stinging insects like
bees, wasps and ants - are generally not lethal.)  Which ones are the most
poisonous?  Any attempt at classification results in qualification.  This much
can be said:  The venom of rattlesnakes is responsible for more deaths, more
hospitalizations and more crippling injuries than the venom of any other animal
in North America.  Below is a field guide to each of the five venomous groups,
how to avoid them - and what to do if it's just not your day.

Pit Vipers -

So called because of the heat-sensing "pit" or opening beneath each eye that's
used to track prey in darkness, this family of snakes includes three species:
Crotalus( the rattlesnakes, of which 32 species and 65-70 subspecies have been
identified in the US alone), Agkistrodon (copperheads and cottonmouths) and
Sistrurus (pigmy rattlers and massasaugas).

Bites from any of the, even the most potent rattlesnakes, rarely result in
death.  Still, if you are bitten get to a hospital.  Don't apply a tourniquet
or ice.  Don't use a snakebite kit.  Don't cut the puncture wound and try to
suck out the venom.  In fact, there is no good first aid for rattlesnake bite.
"We'd rather tell people that than have them doing the wrong thing and lose
their life or an arm," said Boyer.  If you must do something, she said,
"elevate and immobilize the limb, rest quietly, and don't freak out."  Most of
the popular literature on snakebite is out of date, and some hospital
emergency-room physicians may still attempt to use ice.  Some may even want to
do surgery.  Don't let them.  Almost all cases of amputation after snakebite
are actually the result of using ice, a tourniquet or both.  Surgery is
necessary only in extremely rare cases.  If you're not in an area where
snakebite is common, insist that the doctors call the Regional Poison Control
Center (listed on the inside cover of the phone book).

The sole treatment is a 1950's era rattlesnake antivenom made from horse serum
(antibodies derived from the blood of horses), which is reasonably effective in
most cases.  But almost everyone who is treated with rattlesnake antivenom can
count on some level of serum sickness - a natural allergic reaction.  Still,
that is usually preferable to the effects of untreated snakebite.  Boyer said,
"It's a lousy, stinking product that causes a lot of problems, but there's
nothing else around."

The cure for snakebite is to avoid it.  It's not that difficult.  Snakes
generally shun people.  If you see one, move away from it.  A rattlesnake can
strike an object up to a distance equal to half it's body length.  The largest
rattler on record in the US was around seven feet long, so if you remain just
four feet away from any snake you encounter, you can take photos, you can sing
Pink Floyd songs, but you're unlikely to be bitten.

Some people like to chop the head off a rattlesnake and take it with them.  Bad
idea.  A rattlesnake can bite up to an hour after decapitation.  A "spasm" from
a dead snake will reflexively deliver the full load of venom and can be worse
than a live snakebite.  It's nature's way of telling you:  Leave them be.

The question most people ask:  Am I going to die?  The answer:  Yes, but
probably not today.  While envenomation by a pit viper can result in the loss
of a finger, hand, arm or leg, in the US it's not likely to be lethal.
Coral Snakes

Members of the family Elapidae include cobras, mambas, kraits, and coral
snakes.  There are two species of coral snakes in the US, the eastern coral
snake and the Arizona coral snake.  The eastern coral's venom is a powerful
neurotoxin that, on occasion, has caused deaths.  At first there may be no
symptoms, and local injury is often small with little swelling or tissue
damage.  But within a few hours, the victim may experience a cascading sequence
of symptoms, beginning with lethargy, nausea, weakness, and trembling or
twitching.  This leads to convulsions, paralysis, respiratory failure and, in
some instances, death.

No deaths from Arizona, or western corals have ever been reported.

Coral snakes are brightly colored with borad bands that encircle the body,
making a pattern beginning with a black snout; black, yellow, red, yellow,
black, yellow, red, yellow.  The yellow may appear white or ivory.  Unlike
rattlesnakes, coral snakes have round (not elliptical) pupils and fixed fangs.
The Arizona coral snake lives in southern Arizona, the southwest corner of New
Mexico and Texas.  The eastern coral snake, which is larger can be found in
North Carolina, South Carolina, Arkansas, Alabama, Georgia, Mississippi,
Florida, Louisiana, and Texas.

People have come to believe they can handle coral snakes with impunity because
they won't bite.  Some say they can even use a coral snake as a bracelet.  The
fact is that coral snakes bite unpredictably.  It is difficult for a coral
snake to bite a human, because of it's fixed fangs and small head (even in the
larger eastern coral snakes).  People often handle them for hours without
incident, only to be bitten for the reasons that only a coral snake could tell
you.

Venom is delivered via grooves in the teeth, rather than injected by hypodermic
action, which is why coral snakes like to hang on for awhile.  If you are
bitten, pull the snake off.  The less time you give it, the less venom you
get.  A bite by an eastern coral snake is a major medical emergency.  Get to a
hospital immediately.  There is a horse serum antivenom for the eastern coral
snake, and it is the only effective treatment.  No antivenom exists for the
western coral, whose bite is usually not fatal.  But hospital care is
important, and a tetnus shot is probably a good idea.

Scorpions

Arthropods have been on earth more than 400 million years, but only one species
in the US is potentially lethal, the bark scorpion.  It is confined mostly to
the southwest.  Mexico is home to seven lethal species.

Once you have seen a scorpion, you won't forget what it looks like; claws that
snatch and a hooked stinger hovering on a five segment tail.  They come in
colors ranging from straw to pink to brown to black and in sizes from an inch
or less to five inches.  The most common in the southwest is also the largest,
the giant hairy scorpion, but its venom is not considered dangerous.  As a
rule, specialists say, the thicker the claws, the less dangerous the scorpion;
the viciously venomous ones usually have slim pincers.  The bark scorpion is
generally straw-colored with elongated tail segments - and slim pincers.  It is
only about an inch long at maturity.

Bark scorpions are so called because they like to hide in the bark of trees.
Unfortunately, they also like to hide in the drains of your sinks or in your
shoes at night.  They like any moist, dark, protected place.  A sweaty shirt
thrown on the floor might make an inviting hideout, too.

The scorpion grips its prey with it's crablike claws and then whips its tail
over its back to inflict a sting.  (Scorpions do not bite.)  As with snakes, 90
percent of stings are on hands or arms.  Some first aid can help.  Ice and
acetaminophen are good for pain relief.  Apply a single ice cube, 10 minutes
on, 10 minutes off.  (Don't immerse the wound in ice water.) If the victim is a
child, a visit to the emergency room is in order.

Bark scorpion venom contains at least five potent neurotoxins.  Its sting is
very painful, though the wound may not swell much at first.  It is generally
not life-threatening to healthy adults.  The classic symptoms of a serious
reaction, usually seen only in children, include uncontrollable thrashing of
the arms and legs and roving eyes.  Adults may experience mild twitching of the
facial muscles, cramps, nausea and anxiety.  Infants are especially at risk of
respiratory failure.  Though some 8,000 scorpion stings are reported in Arizona
alone each year, there have been no fatalities since 1958.

Although antivenom is given for scorpion stings in Mexico, none has been
approved by the FDA for use in the U.S.

Widow Spiders

All five species in the United States, including the black, red and brown
widows, are poisonous.  Only females have fangs long enough to puncture human
skin and inject venom.

The black widow is shiny black with a body the size of a nickel and a red
hourglass marking on its stomach.  The hourglass may also be yellow or orange.
Its characteristic web is tangled, strong, nd chaotic looking (like the fake
spider web that people spread around at Halloween).  They are found in any
protected place indoors- closets, attics, basements - or outside, under
woodpiles, animal burrows, barns and beneath ground cover.

Mature females tend to stay in their webs.  They don't prowl.  The black widow
lies in its web and bites when the web is disturbed.  The classic human
encounter involves a spider that spins its web back and forth across the the
seat of an outhouse to catch flies that move back and forth through that
opening.   "More men and boys are bitten in outhouses because they have
dangling appendages,"  Jude McNally said.

Black widow spider venom is a powerful neurotoxin.  There may be two puncture
wounds and a pale coloring to the skin around them.  Major pain begins in about
half an hour, an ache that tends toward numbness.  Systemic symptoms may take
up to two hours to appear.  Muscle pain near the bite spreads to the abdomen,
back, and legs - or it may simply appear in those locations.  Other symptoms
include difficulty in breathing, muscle twitching, anxiety, swelling of the
eyelids, headache and nausea.

But don't wait for symptoms to appear.  Go to the emergency room where you may
receive muscle relaxants and narcotics for pain.  An antivenom exists, but
allergic reactions to it may be much more severe than the spider bite itself.
It is recommended only for pregnant women or for cases involving hypertension,
seizures or respiratory failure.  Deaths are very rare; none have been recorded
in the United States in more than 15 years.

Brown Spider

The 12 species in the US (out of more than 100 that are known) include the
infamous brown recluse spiders and the Arizona brown spiders.  All are
seriously dangerous to humans.  Called "violin spiders" because of violin
shaped marking on the back, the brown spider's body is usually a half to a full
inch in length.  Their legs are two or three times as long as their bodies.
Colorings can vary from gray to orange to rust to brown.  Unlike other spiders,
which have four pairs of eyes, browns have three pairs.

Brown spiders range across the south and southwest and up through Iowa and
Illinois (but no farther north than southern Wisconsin).  They like to hide in
dark corners indoors, or under objects or in the nests of animals outdoors.
Their webs are dense, disorganized, sticky and very white or tinged blue.

Spider venom is injected through a hollow fang.  Spiders bite, they don't
sting.  Like most venoms, the substances injected by the brown spiders will
digest tissue.  People who have been bitten by a brown spider often feel
nothing at first.  But an aching sets in at the site after six to eight hours,
as blood vessels are closed off by the poison and tissue begins to starve.  A
blister appears and there may also be flulike symptoms.  The blister breaks,
leaving a black area of dead or dying tissue.  The bite may appear as a dark
spot, with a white area surrounding it and a red ring around that - the
so-called bull's-eye lesion.  Fortunately, spiders are small and people are
big, and fatalities are extremely rare in the US.  More commonly, the bite of a
brown spider results in an ugly black patch of dead tissue that rots and falls
off after a few weeks, leaving a deep ulcer that takes many months to heal. 

If bitten, go to the emergency room.  don't wait for symptoms to appear.  A
severe reaction may range from nausea to a high fever that can last a week.  In
most cases, analgesics (such as aspirin) are given for pain while doctors watch
for systemic reactions.  Usually nothing more is required.  An antivenom is
being tested.

Gila Monsters

There are two venomous lizards, the Gila monster and the Mexican beaded
lizard.  The Gila monster lives in the Sonoran Desert across southwestern
Arizona and down into northwestern Mexico, as well as in the Chihuahuan Desert
in northwestern Arizona, the southern tip of Nevada (around Las Vegas) and the
southwestern corner of Utah (vicinity of St. George).  They also live in a
small area in eastern California.  The Mexican beaded lizard occurs in Mexico
only.

The markings on these saurians are never quite the same, yet no one seems to
mistake a Gila monster for anything else.  They are usually black and pink (or
coral) colored.  The largest lizards in the US, they can reach 20 inches in
length, and the largest specimens can weigh up to two pounds.  The Mexican
beaded lizard is a similar looking animal with a longer tail than the Gila
monster.  It can grow to three feet in length.  Think about it.

Most active in March, April, and May, Gila monsters are not easy to find.  They
don't crawl up and bite people.  They are slow and torpid animals.  Since it's
virtually impossible to be bitten without picking the animal up, don't pick up
any Gila monsters.

Their delivery of venom depends on how long they can hang on and chew.  If you
can get their jaws pried open and take your hand out of the lizard's mouth,
chances are that little venom will enter your system.  Trying to shake the
lizard off won't work well.  Place it on the ground and pry its jaw open with a
stick, knife, or other tool.  Some people suggest holding a flame beneath its
jaw or submerging it in water, or even squirting lighter fluid on its snout.
This last technique presents us with the possibility of someone running in
circles with a flaming lizard attached to his hand.  The bite is reported to
produce "instant and excruciating pain."

Gila monster venom is similar to rattlesnake venom in its action.  Because the
venom contains fewer of the anticoagulant agents and digestive enzymes, tissue
damage will be lessened or absent.  Gila monster bites are rare.  But the venom
is highly toxic and there's no way to tell how much you received.  Weakness,
dizziness and shock could result.   That may not be a reliable criterion, since
some people grow weak and dizzy at the very thought of having a lizard attached
to their hand.  No human deaths resulting solely from Gila  monster venom have
been documented.

No antivenom exists.  The most important thing the docutor can do is remove the
Gila monster's teeth, which break off in the wound and cause infection.  A
tetanus shot isn't a bad idea either.  It's impossible to give this advice
often enough:  Don't apply ice or a tourniquet.  Do remove the lizard.  Do get
to a hospital.

If you do happen to die from a Gila monster bite, they will probably erect a
statue on the spot.

Excerpt from Men's Journal March 95 





Article 37244 of rec.backcountry:
From: "David" <ny@mindspring.com>
Newsgroups: rec.backcountry
References: <42aad888$1@darkstar>
Subject: Re: [l/m 7/25/2001] Snakebite:	Distilled Wisdom (11/28) XYZ
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"Eugene Miya" eugene@cse.ucsc.edu:
"A number of field studies have shown that a Sawyer's Extractor (Sawyer's
 Products, Safety Harbor, Fla), which provides about one atmosphere of
 negative pressure, is effective in extracting venom from the bite site . . 
."

David ny@mindspring.com:
The information above is outdated and dangerous.  Read:

Snakebite Suction Devices Don't Remove Venom: They Just Suck
Sean P. Bush, MD
Department of Emergency Medicine, Loma Linda
University School of Medicine, Medical Center and Children's
Hospital, Loma Linda, CA.
Annals of Emergency Medicine. 2004;43:187-188.

It was only a few decades ago that incision and suction were recommended 
snakebite first aid. However, concerns arose about injuries and infections 
caused when laypersons made incisions across fang marks and applied mouth 
suction. Meanwhile, several snakebite suction devices (eg, Cutter's 
Snakebite Kit, Venom Ex) were evaluated, and it was determined that they 
were neither safe nor effective.1 So, recommendations changed, and 
mechanical suction without incision was
advocated instead.2-5 It seemed intuitive that suction alone would probably 
remove venom and should not cause harm.  However, when the techniques were 
studied rigorously, quite the opposite was discovered.

One of the most popular suction devices, the Sawyer Extractor pump (Sawyer 
Products, Safety Harbor, FL), operates by applying approximately 1 atm of 
negative pressure directly over a fang puncture wound (or wounds) without 
making incisions. The manufacturer instructs that the device be applied 
within 3 minutes of the snakebite and left in place for 30 to 60 minutes. 
For many years, most agreed (including the Wilderness Medical Society and 
the American Medical Association) that the Extractor might be beneficial and 
would probably cause no harm.2-5 Others suggested that it could exacerbate 
tissue damage, adding insult to injury after viper envenomation.6-9 In this 
issue of Annals, the Extractor's inefficacy has been further confirmed with 
a well-designed study and fully detailed manuscript.10

In their prospective experimental trial, a human model was used to test the 
amount of radioactively labeled mock venom that could be removed by an 
Extractor after subcutaneous injection with a 16-gauge hypodermic needle. 
The investigators measured radioactive count as an approximation of the 
amount of venom removed. The bottom line: the Extractor removed
0.04% to 2.0% of the envenomation load. The authors conclude that this is a 
clinically insignificant amount and that the Extractor is essentially 
useless.The main limitation of their study is that they could not use real 
venom.

The study by Alberts et al10 corroborates other studies that have tested the 
efficacy and safety of the Extractor. Using a porcine model and real 
rattlesnake venom in a randomized, controlled trial, Bush et al11 measured 
swelling and local effects as outcome variables after application of an 
Extractor to artificially envenomated extremities. The conclusion of the 
study was that the Extractor did not reduce swelling, but resulted in 
further injury in some subjects. Specifically, circular lesions identical in 
size and shape to the Extractor suction cups developed where the devices had 
been applied. These lesions subsequently necrosed, sloughed, and resulted in 
tissue loss that prolonged healing by weeks. Similar injuries after 
Extractor use have been noted in human patients.1,12

In another study, Extractors were applied to 2 human patients immediately 
after rattlesnake envenomations, and the device was left in place until its 
cup filled with serosanguinous fluid 5 times, although the authors do not 
specify the volume(s) of fluid obtained. The concentration of venom was 
measured in the fluid removed using an enzyme-linked immunosorbent assay.13 
There were no control subjects, and this study has only been published in 
abstract form. Ironically, this abstract is cited amongst the main 
supporting evidence for the Extractor.4,14  However, a closer review of the 
results reveals that the concentration of venom in the serosanguinous fluid 
removed was only about 1/10,000th the concentration of rattlesnake 
venom.Alberts et al10 similarly noted that although a relatively large 
volume of bloody fluid was pulled from the puncture
site, it contained virtually no venom. Most interestingly, Alberts et al 
found that the amount of venom in the fluid that spontaneously oozed from 
the wound was greater than the amount of venom in the Extractor aspirate. It 
is possible in these 2 experiments that the fluid obtained came from 
superficial tissues, and that the strong suction exerted by the device 
collapses the distal portion of the fang tract where the venom is deposited, 
thereby reducing the amount of venom that would spontaneously ooze out. This 
suggests, like the study by Bush et al,11 that the Extractor might make the 
envenomation worse by paradoxically increasing the amount of venom left in 
the wound.

Although each of these 3 studies was done independently of each other and 
using different methodology,  they arrive at the same conclusion: the 
Extractor does not work, and it could make things worse. The only study that 
suggests the Extractor removes a clinically important amount of venom is an 
uncontrolled experiment using a rabbit model.15 Unfortunately, this study 
was only published as an abstract, and the methodology is not described in 
detail. Furthermore, its results are suspect for many reasons. Rabbits have 
a very thin subcutaneous layer, unlike humans (and pigs).16 Most snake 
envenomations are thought to occur in the subcutaneous layer.17 It is 
possible that in Bronstein et al's15 investigation the injected venom 
collected just under the rabbit's skin, where it was easily suctioned back 
out by the device. Because this inadequately documented single abstract 
reports a finding that is vastly different from all the other studies that 
follow, its conclusions are questionable and may be erroneous.

If there was controversy before, the study by Alberts et al10 adds to the 
growing pile of evidence against the Extractor. This study should change our 
practice. We should stop recommending Extractors for pit viper bites, and 
the manufacturer should certainly stop advertising that they are recommended 
medically as the only acceptable first aid device for snakebites.  Because 
it is becoming clear that this gadget does not work, future investigations 
should focus on other first aid techniques, such as pressure-immobilization 
or others yet to be discovered. Meanwhile, the best first aid for snakebite 
is a cell phone and a helicopter.

R E F E R E N C E S

1. Hardy DL. A review of first aid measures for pitviper bite in North 
America with an
appraisal of Extractor suction and stun gun electroshock. In: Campbell JA, 
Brodie ED
Jr., eds. Biology of the Pitvipers. Tyler, TX: Selva Publishing; 
1992:405-414.

2. Forgey WW, ed. Wilderness Medical Society Practice Guidelines for 
Wilderness
Emergency Care. Merrillville, IN: ICS Books; 1995.

3. Forgey WW. More on snake-venom and insect-venom extractors [letter]. N 
Engl J
Med. 1993;328:516.

4. Gold BS. Snake venom extractors: a valuable first aid tool [letter]. Vet 
Hum Toxicol.
1993;35:255.

5. Forgey W, Norris RL, Blackman J, et al. Viewpoints: response. J Wild Med.
1994;5:216-221.

6. Gellert GA. Snake-venom and insect-venom extractors: an unproved therapy 
[letter].
N Engl J Med. 1992;327:1322.

7. Gellert GA. More on snake-venom and insect-venom extractors [letter]. N 
Engl J
Med. 1993;328:516-517.

8. Winkel KD, Hawdon GM, Levick N. Pressure immobilization for neurotoxic 
snake
bites. Ann Emerg Med. 1999;34:294-295.

9. Warrell DA. Snake bite and snake venoms. Quart J Med. 1993;86:351-353.

10. Alberts MB, Shalit M, LoGalbo F. Suction for venomous snakebite: a study 
of
"mock venom" extraction in a human model. Ann Emerg Med. 2004;43:181-186.

11. Bush SP, Hegewald K, Green SM, et al. Effects of a negative-pressure 
venom
extraction device (Extractor) on local tissue injury after artificial 
rattlesnake envenomation
in a porcine model. Wilderness Environ Med. 2000;11:180-188.

12. Bush SP, Hardy Sr DL. Immediate removal of Extractor is recommended 
[letter].
Ann Emerg Med. 2001;38:607-608.

13. Bronstein AC, Russell FE, Sullivan JB. Negative pressure suction in the 
field treatment
of rattlesnake bite victims [abstract]. Vet Hum Toxicol. 1986;28:485.

14. Norris RL. A call for snakebite research. Wilderness Environ Med. 
2000;11:149-151.

15. Bronstein AC, Russell FE, Sullivan JB, et al. Negative pressure suction 
in the field
treatment of rattlesnake bite [abstract]. Vet Hum Toxicol. 1985;28:297.

16. Hobbs GD. Brown recluse spider envenomation: is hyperbaric oxygen the 
answer?
Acad Emerg Med. 1997;4:165-166.

17. Gold BS, Barish RA, Dart RC, et al. Resolution of compartment syndrome 
after rattlesnake
envenomation utilizing non-invasive measures. J Emerg Med. 2003;24:285-288.

Source:
http://www.med.unc.edu/emergmed/teachme/Journal%20club/journal%20club%20June%202004,%20snake%20bite/snake%20bite%20suck%20ANNALS.pdf

See, also:

Annals of Emergency Medicine
Volume 43, Issue 2 , February 2004, Pages 181-186
Suction for venomous snakebite*1
A study of "mock venom" extraction in a human model
Michael B. Alberts MD, , a, Marc Shalit MDa and Fred LoGalbo MDb
a Department of Emergency Medicine, University Medical Center, University of 
California, San Francisco, Fresno
b Department of Radiology, Community Medical Center of Central California, 
Fresno
An abstract of this paper is printed below.  The full text is available at:
http://www.med.unc.edu/emergmed/teachme/Journal%20club/journal%20club%20June%202004,%20snake%20bite/venom%20extractor%20annals.pdf

Study objective

We determine the percentage of mock venom recovered by a suction device 
(Sawyer Extractor pump) in a simulated snakebite in human volunteers.

Methods

A mock venom (1 mL normal saline solution, 5.0 mg albumin, 2.5 mg aggregated 
albumin) radioactively labeled with 1 mCi of technetium was injected with a 
curved 16-gauge hypodermic needle 1 cm into the right lateral lower leg of 8 
supine male volunteers aged 28 to 51 years. The Sawyer Extractor pump was 
applied after a 3-minute delay, and the blood removed by suction was 
collected after an additional 15 minutes. A 1991 Siemens Diacam was used to 
take measurements of the
radioactive counts extracted and those remaining in the leg and body.

Results

The "envenomation load," as measured by mean radioactivity in the leg after 
injection, was 89,895 counts/min. The mean radioactivity found in the blood 
extracted in the 15 minutes of suction was 38.5 counts/min (95% confidence 
interval [CI] ?33 to 110 counts/min), representing 0.04% of the envenomation 
load. The postextraction leg count was less than the envenomation load by 
1,832 counts/min (95% CI ?3,863 to 200 counts/min), representing a 2.0% 
decrease in the total body venom load.

Conclusion

The Sawyer Extractor pump removed bloody fluid from our simulated snakebite 
wounds but removed virtually no mock venom, which suggests that suction is 
unlikely to be an effective treatment for reducing the total body venom 
burden after a venomous snakebite.
 




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