Dry gangrene is the necrosis, or death, of a particular part of the body. It occurs when there is not enough blood flow throughout the body, and is commonly seen in the skin and extremities. Unlike wet gangrene, there is no bacterial infection or wound that causes this condition.
The condition is caused when there is not enough oxygen delivered to portions of the body; it is common in the extremities because by the time the blood has circulated this far, it has lost much of its oxygen in other parts of the body. This oxygen deficiency is caused by arteries that are too narrow; arteries are the large blood vessels that carry oxygenated blood away from the heart and throughout the body. Thus this condition occurs in individuals with narrow arteries caused by a variety of factors, including diabetes, high cholesterol, poor circulation, smoking, or hereditary and genetic reasons.
Dry gangrene happens slowly, and the condition gets worse over time, with the afflicted area gradually growing. First, the skin in the localized area becomes cold to the touch. Eventually it will begin to turn first red and then will fade to brown. Once the skin begins to turn black, it will also take on a dry, shriveled appearance and begin to peel off. The area where dry gangrene is beginning will often be numb as well throughout the advance of the condition.
As the skin begins to peel, it can very easily become infected if not properly cared for. In some cases this can lead to wet gangrene, which occurs when an infection in an open wound blocks blood flow to the area completely, and cells from the immune system cannot fight the infection. This progression makes it vital to get cases of dry gangrene looked after immediately.
Treatment for dry gangrene usually involves determining the cause of the lack of sufficient oxygen to the afflicted area. Once this is determined, it can be treated to restore the blood flow and revitalize the dying area. For some individuals, this can mean surgery to open some of the most crucial arteries that supply the area. Some medical professionals may prescribe other types of treatment in order to stop the decay and prevent further infection. If there is the threat of infection in the skin that has already died, maggots can be used to clean up the dead tissue and bacteria, preventing infection from spreading into the bloodstream and turning the condition into wet gangrene.