gangrene

Gangrene is the death and decay of body tissue resulting from an inadequate blood supply, infection, or both. It most often affects the extremities, such as the toes or fingers, but can involve any part of the body or internal organs in severe cases.

Dry gangrene develops when arterial blood flow gradually decreases, usually due to atherosclerosis or diabetes. The affected tissue becomes dry, shriveled, and turns dark brown to black.

Wet gangrene occurs when infection superimposes on ischemic tissue, causing swelling, blistering, a wet appearance, and a foul odor. It spreads rapidly and can lead to sepsis.

Gas gangrene is typically caused by certain Clostridium bacteria that produce gas within tissues. It causes severe pain, swelling, crepitus (a crackling sensation under the skin), and rapid tissue destruction.

Causes include chronic vascular disease, acute injuries, frostbite, diabetes, infection in compromised tissue, and immune suppression. The processes may be ischemic, infectious, or a combination.

Symptoms include changes in skin color, numbness or loss of sensation, foul-smelling discharge, fever, and signs of systemic illness in severe cases.

Diagnosis is based on clinical examination, imaging (such as X-ray or CT to detect gas in soft tissues), laboratory tests, and culture of tissue or blood.

Treatment requires urgent medical care and may include surgical debridement or amputation to remove dead tissue, broad-spectrum intravenous antibiotics, and procedures to restore blood flow if feasible. In some cases, hyperbaric oxygen therapy is used as an adjunct. Mortality is higher for wet and gas gangrene and for cases associated with sepsis.

Prevention focuses on managing risk factors (diabetes, vascular disease), prompt treatment of wounds, good wound care, and early medical evaluation for suspected infection.