Aetiology

Many factors may cause gangrene including:

• arterial obstruction - gangrene developing secondary to other disease pathology such as thrombosis of an atherosclerotic artery, embolus from heart in atrial fibrillation or after coronary thrombosis, arteritis with neuropathy in diabetes, Buerger's disease, arterial shutdown in Raynaud's disease, and ergotism, certain intra-arterial injections, for example cytotoxic substances
• infection - boils and carbuncles, gas gangrene, Fournier's scrotal gangrene
• trauma - direct e.g. pressure sores; indirect - injury of vessels away from the site of the gangrene e.g. pressure on the popliteal artery by the lower end of a fractured femur
• physical - e.g. burns, scalds, frostbite, chemicals
• peripheral vein thrombosis - e.g. in venous gangrene