Necrosis << neh KROH sihs >> is the death of living tissue. Necrosis can occur as a result of injury, infection, cancer, radiation, or toxins (poisons). Necrosis is the body’s response to some disruption in normal, living tissue. It can occur in any part of the body.
The body continually recycles itself by developing new cells to replace old cells. Normally, the body uses immune system cells called phagocytes to remove dead tissue. However, if destruction of tissue occurs suddenly in an injury or through disease, the immune system may not activate quickly enough to do so. The dead tissue builds up in the body.
Necrosis can occur in anyone, especially someone with a wound that is exposed to bacteria. People at risk of necrosis include those who have been exposed to radiation or who have recently had surgery leading to an infection. People with arthritis may develop necrosis around a joint, such as the hip, where blood flow is reduced through inflammation. People with diabetes or peripheral vascular disease may develop necrotic pressure ulcers, especially in their lower extremities. Peripheral vascular disease is any disease of the blood vessels that occurs outside the heart and brain. An ulcer is a sore. Pressure ulcers, commonly called bedsores, are caused by prolonged pressure on the body. Drug abusers who inject drugs using unsterilized needles may suffer necrotic ulcers as bacteria infect the injection site.
Symptoms
of necrosis include pain or fever. Necrosis in the skin may cause the skin to turn black in color. Necrosis inside the body can sometimes be seen in an X-ray image. Laboratory tests will show elevated levels of a protein called creatine kinase in the blood. This protein is released into the bloodstream when muscle or other tissue is damaged.
Necrotic tissue releases various chemicals that can destroy surrounding healthy tissue. Bacteria from necrotic tissue can invade the bloodstream, causing septicemia (sometimes called blood poisoning). A condition called gangrene can develop if the decayed tissue is not removed.
Treatment
of necrosis requires debridement (removal) of the dead tissue to allow healthy tissue to repair itself. Tissue cannot heal or be repaired once it has become necrotic. A necrotic finger or toe may drop off naturally. Otherwise, surgery may be required to remove the decayed tissue. If necrosis affects a larger area, amputation may be necessary.
