Definition of Gas gangrene:

Gas gangrene is a potentially deadly form of tissue death (gangrene).

See also: Necrotizing subcutaneous infection

Causes, incidence, and risk factors:

Gas gangrene is rare in the United States. The condition is most often caused by a bacteria called Clostridium perfringens. However, it also can be caused by Group A streptococcus. Staphylococcus aureus and Vibrio vulnificus can cause similar infections.

Under low-oxygen (anaerobic) conditions, Clostridium produces toxins that cause tissue death and related symptoms.

Gas gangrene generally occurs at the site of trauma or a recent surgical wound. The onset of gas gangrene is sudden and dramatic. About a third of cases occur on their own. Patients who develop this disease in this manner often have underlying blood vessel disease (atherosclerosis or hardening of the arteries), diabetes, or colon cancer.

Clostridium bacteria produce many different toxins, four of which (alpha, beta, epsilon, iota) can cause potentially deadly syndromes. The toxins cause damage to tissues, blood cells, and blood vessels.