Dermatitis is a general term used to describe inflammation of the skin, usually characterized by a pink or red rash that itches.
Contact dermatitis is an allergic reaction to something that irritates the skin and is manifested by one or more lines of red, swollen, blistered skin that may itch or weep. It usually appears within 48 hours after touching a substance to which the skin is sensitive. The condition is more common in adults than in children.
Contact dermatitis can occur on any part of the body, but it usually affectsthe hands, feet, and groin. It usually does not spread from one person to another, nor does it spread beyond the area exposed to the irritant unless affected skin comes into contact with another part of the body. However, in the case of some irritants, such as poison ivy, contact dermatitis can be passed toanother person or to another part of the body.
Allergic reactions are genetically determined, and different substances causecontact dermatitis to develop in different people. A reaction to resin produced by poison ivy, poison oak, or poison sumac is the most common source. Flowers, herbs, and vegetables can also affect the skin of some people. Burns and sunburn increase the risk of dermatitis, and chemical irritants that can cause the condition include chlorine, cleansers, detergents and soaps, fabric softeners, glues used on artificial nails, perfumes, and topical medications.Contact dermatitis can develop when the first contact occurs or after years of exposure.
Stasis dermatitis is characterized by scaly, greasy looking skin on the lowerlegs and around the ankles. A consequence of poor circulation, it occurs when leg veins can no longer return blood to the heart as efficiently as they once did. When that happens, fluid collects in the lower legs and causes them to swell. Stasis dermatitis can also result in a rash that can break down intosores known as stasis ulcers, in which case a doctor should be notified immediately.
Nummular dermatitis generally affects the hands, arms, legs, and buttocks ofmen and women older than 55 years of age. This stubborn inflamed rash forms circular, sometimes itchy, patches and is characterized by flares and periodsof inactivity. The cause of nummular dermatitis is not known, but it usuallyoccurs in cold weather and is most common in people who have dry skin. Hot weather and stress can aggravate this condition, as can allergies, fabric softeners, soaps and detergents, wool clothing, and bathing more than once a day.
Atopic dermatitis is characterized by itching, scaling, swelling, and sometimes blistering. In early childhood it is called infantile eczema and is characterized by redness, oozing, and crusting. It is usually found on the face, inside the elbows, and behind the knees. It can be caused by allergies,asthma, or stress, and there seems to be a genetic predisposition foratopic conditions.
There may also be a genetic predisposition to seborrheic dermatitis, which may be dry or moist and is characterized by greasy scales and yellowish crustson the scalp, eyelids, face, external surfaces of the ears, underarms, breasts, and groin. In infants it is called "cradle cap." Seborrheic dermatitis isusually caused by overproduction of the oil glands. In adults it can be associated with diabetes mellitus or gold allergy. In infants and adults itmay be caused by a biotin deficiency.
To diagnose dermatitis, the doctor may scrape off a small piece of affected skin for microscopic examination, or perform patch tests--dabbing small amounts of a suspected irritant onto skin on the patient's back. The doctor will ask about potential irritants that have recently come into contact with the affected area.
Treating contact dermatitis begins with eliminating the source of irritation.If the irritant cannot be avoided completely, the patient should wear glovesand other protective clothing whenever exposure is likely to occur. Prescription or over-the-counter corticosteroid creams can lessen inflammation and relieve irritation. Creams, lotions, or ointments not specifically formulated for dermatitis can intensify the irritation. Oral antihistamines are sometimes recommended to alleviate itching, and antibiotics are prescribed if the rash becomes infected.
Patients who have a history of dermatitis should remove their rings before washing their hands. They should use bath oils or glycerine-based soaps and bathe in lukewarm saltwater. Patting rather than rubbing the skin after bathingand thoroughly massaging lubricating lotion or nonprescription cortisone creams into still-damp skin can soothe red, weepy nummular dermatitis. Highly concentrated cortisone preparations should not be applied to the face, armpits,groin, or rectal area. Periodic medical monitoring is necessary to detect side effects in patients who use such preparations on rashes covering large areas of the body.
Coal-tar salves can help relieve symptoms of nummular dermatitis that have not responded to other treatments, but these ointments have an unpleasant odorand stain clothing.
Patients who have stasis dermatitis should elevate their legs as often as possible and sleep with a pillow between the lower legs. Tar or zinc paste may also be used to treat stasis dermatitis. Because these compounds must remain in contact with the rash for as long as two weeks, the paste and bandages mustbe applied by a nurse or a doctor.
Coal-tar shampoos may be used for seborrheic dermatitis that occurs on the scalp. Sun exposure after the use of these shampoos should be avoided because the risk of sunburn of the scalp is increased.
A number of botanical and homeopathic therapies can be useful for skin conditions These include burdock root (Arctium lappa), calendula (Calendula officinalis) ointment, and chamomile (Matricaria recutita) ointment.
A patient who has dermatitis should notify a doctor if fever develops,the skin oozes or other signs of infection appear, if symptoms do not beginto subside after seven days' treatment, or if he/she comes into contact withsomeone who has a wart, cold sore, or other viral skin infection.