Dry gangrene describes localized tissue death caused by loss of blood supply. The body tissues are kept alive by a constant supply of oxygen and nutrients delivered by the blood, which also carries away tissue waste products. Inadequate blood supply due to atherosclerosis (fatty plaques in the arteries), a blood clot or trauma causes death of the affected tissues. Atherosclerosis of the arteries in the extremities is called peripheral arterial disease, or PAD. PAD is the leading cause of dry gangrene. Recognizing the early signs of dry gangrene and getting treatment may prevent tissue death.
Early in the process of dry gangrene, the tissues are suffering the effects of decreased oxygen and the buildup of waste products but remain alive. These circumstances commonly cause pain, which is usually dull and aching. Eventually, the pain gives way to numbness as the nerve tissues die.
Changing Skin Color
As blood supply diminishes, the skin of the affected area may appear dark red if situated below the heart. If the area is lifted to a position above the heart, it quickly blanches to an unnatural white color. When the blood supply is completely obstructed, the affected area appears pale--though it will go through a subsequent series of color changes as the dead tissue decays.
An area of skin with insufficient blood supply is cool to the touch. If you put one hand on the affected area and the other on an area with normal blood supply, you can easily feel a marked temperature difference. As dry gangrene progresses and the tissue dies, the area becomes cold.
Dry gangrene is often heralded by the formation of one or more skin ulcers--crater-like wounds in the skin. The ulcers are typically painful. A black rim of dead tissue commonly surrounds the ulcer; this tissue may be the harbinger of wider tissue loss in the area. Ulcer depth is an indicator of the probability of the development of full-blown dry gangrene requiring amputation.
If you experience any signs of dry gangrene, seek medical attention right away. Early treatment improves the chance for successful treatment of this serious condition.
- Types of Bacteria: What is Gangrene?
- National Heart, Lung and Blood Institute: Peripheral Arterial Disease
- Short Textbook of Surgery; Himansu Roy; 2010