Gas gangrene occurs as a result of infection with Clostridium bacteria that, under anaerobic (low oxygen) conditions, produce toxins that cause tissue death and associated symptoms. Gas gangrene is rare, with only 1,000-3,000 cases yearly in the U.S. Gas gangrene generally occurs at the site of trauma or a recent surgical wound. About a third of cases occur spontaneously. Patients who develop this disease spontaneously often have underlying blood vessel disease (atherosclerosis or hardening of the arteries), diabetes, or colon cancer. The onset of gas gangrene is sudden and dramatic. Inflammation begins at the site of infection as a pale-to-brownish-red and extremely painful tissue swelling. Gas may be felt in the tissue as a crackly sensation when the swollen area is pressed with the fingers. The edges of the infected area expand so rapidly that changes are visible over a few minutes. The involved tissue is completely destroyed. Clostridium bacteria produce many different toxins, four of which (alpha, beta, epsilon, iota) can cause potentially fatal syndromes. In addition, they cause tissue death (necrosis), destruction of blood (hemolysis), local decrease in circulation (vasoconstriction), and leaking of the blood vessels (increased vascular permeability). These toxins are responsible for both the local tissue destruction and the systemic symptoms (the other symptoms that occur throughout the body). Systemic symptoms develop early in the infection. These consist of sweating, fever, and anxiety. If untreated, the individual develops a shock -like syndrome with decreased blood pressure (hypotension), kidney failure, coma, and finally death.
| 
