Gangrene is the destruction of body tissue by a bacteria called Clostridium perfringens, or a combination of streptococci and staphylococci bacteria. C. perfringens is wide-spread in soil and the intestinal tracts of humans and animals. It becomes dangerous only when its spores germinate, producing toxins and destructive enzymes, and germination occurs only inan anaerobic environment (one almost totally devoid of oxygen). Whilegangrene can develop in any part of the body, it is most common in fingers, toes, hands, feet, arms, and legs, the parts of the body most susceptible to restricted blood flow. Even a slight injury in such an area is at high risk ofcausing gangrene. Early treatment with antibiotics such as penicillin, and surgery to remove the dead tissue, will often reduce the need for amputation.Left untreated, gangrene results in amputation of the affected limb and/or death of the patient. Many wounded soldiers lost life and limb to gangrene before sterilization of surgical instruments and the development of antibiotics.
Because blood carries oxygen to all tissues of the body, diseases or injurieswhich interrupt that blood flow increase the risk of gangrene. Diabetes, arteriosclerosis, severe frost bite, blood clots, crushing injuries, andburns are common causes of restricted blood flow. Gangrene is classified intotwo types: dry and wet. Gas gangrene, the most deadly apart from gangrene inthe abdominal organs, falls in the category of wet gangrene. Dry gangrene, in which the skin becomes painful, dark, dries up, and drops off, is less aggressive than moist gangrene, as some healing can occur where the living and dead skin meet. Moist gangrene, on the other hand, spreads quickly and can be fatal. Dying cells leak fluid and the moist environment encourages bacteria togrow and spread rapidly. Symptoms often begin with pain and loss of feelingfollowed by swelling of the skin and blisters which turn black and ooze a foul-smelling discharge. Infection can be accompanied by a fever up to 101°F (38.3°C).
Gas gangrene usually develops from infection following surgery, or when contaminated soil or other foreign matter enters a deep puncture wound, open wounds with muscle damage, or a compound fracture. Bacteria flourish in the moist,oxygen-reduced environment, producing gaseous bubbles which release poison into the body. Infection spreads rapidly through the dying skin, underlying muscle, and bone, which excrete a brown, foul-smelling puss. Ruptured appendixor gallbladder are the most common cause of abdominal gangrene, which is indicated by severe abdominal pain.
Risk factors associated with poor circulation and therefore gangrene are diabetes mellitus, smoking, excessive consumption of alcohol, poor circulation commonly experienced in old age, Raynaud's disease, and Buerger's disease. Individuals in these categories should take precautions such as close examination of extremities for signs of swelling, redness, warmth, or painof the skin; avoid foot injuries by wearing comfortable shoes and keeping toe nails clipped; adhering strictly to dietary and medical regimes recommendedfor diabetes, and stop drinking alcohol and smoking tobacco. If infection issuspected, a doctor's advice should be sought immediately.
In 1994, physicians from Cornell University and New York Hospital reported considerable success with angioplasty to improve blood flow to lower extremities. In 1997, Jeffrey Isner, M.D. and his team at St. Elizabeth's Medical Center in Boston developed a gene therapy called "therapeutic angiogenesis," whichencourages the growth of new blood vessels around restricted vessels. Success was achieved in the legs of eight out of 10 people treated, avoiding the need for amputation.
In 1994, seven people in England died of a "flesh-eating virus," or "galloping gangrene," caused by agroup A streptococcus infection bringing aboutnecrotizing fasciitis, the death of subcutaneous and adjacent tissue.These instances of necrosis were unusual because it usually involves an anaerobic bacteria.