C. perfringens is a normal inhabitant of the GI and female genital tracts; it’s also prevalent in soil. Transmission of infection occurs by entry of organisms during trauma or surgery. Because C. perfringens is anaerobic and spore forming, gas gangrene is usually found in deep wounds, especially those in which tissue necrosis further reduces the oxygen supply. Clostridial bacteria produce four different toxins (alpha, beta, epsilon, and iota) that can cause potentially fatal symptoms. When C. perfringens invades soft tissue, it produces thrombosis of regional blood vessels, tissue necrosis, localized edema, and damage to the myocardium, liver, and kidneys. Such necrosis releases both carbon dioxide and hydrogen subcutaneously, producing interstitial gas bubbles. Gas gangrene usually occurs in the extremities and in abdominal wounds; it’s less common in the uterus.

Possible complications of gas gangrene include renal failure, hypotension, hemolytic anemia, shock, and tissue death, requiring amputation of the affected body part. If left untreated, gas gangrene leads to death.

True gas gangrene produces myositis and anaerobic cellulitis, another form of the condition that involves only soft tissue. Most signs of infection develop within 72 hours of trauma or surgery. The hallmark of gas gangrene is crepitation (a crackling sensation when the skin is touched), which is a result of carbon dioxide and hydrogen accumulation as a metabolic by-product in necrotic tissue. Other typical indications are severe localized and progressive pain, swelling, and discoloration (initially pale, later orange tinted, dusky brown, or reddish), with bullae formation and necrosis within 36 hours of the onset of symptoms. The skin over the wound may rupture, revealing dark red or black necrotic muscle, a foul-smelling watery or frothy discharge, intravascular hemolysis, thrombosis of blood vessels, and evidence of infection spread.