Elderly people, those who have other medical problems, and those in whom the disease has reached an advanced stage have a poor prognosis. Skin Gangrene Gangrene is the death of tissue, usually associated with loss of blood supply to the affected area, followed by bacterial invasion. Gangrene results from an infection caused by clostridia and sometimes by other bacteria. Clostridia are a type of bacteria called anaerobic bacteria, which grow only in the absence of oxygen. Clostridia produce gas as they grow, so the infection is sometimes called gas gangrene.
Infection develops within hours or days after the injury.
Gangrene also may develop in a surgical wound, particularly when the blood supply to the wound is poor. People with poor circulation are particularly at risk. The skin may look pale at first, but it becomes red or bronze and finally green. Infection with clostridia also makes the skin warm and swollen. The fluid from these blisters looks brown and smells foul.