Vasculitis

Inflammation of blood vessels. Vasculitis usually leads to damage to the lining of vessels, with narrowing or blockage, that restricts or stops blood flow. As a result, the body tissues supplied by the affected vessels are damaged or destroyed by ischaemia. Vasculitis is thought to be caused in most cases by the presence of minute bodies, called immune complexes, in the circulating blood. Immune complexes (consisting of antigens bound to antibodies) are normally destroyed by white blood cells, but sometimes adhere to the walls of blood vessels, where they cause inflammation. In some cases, the antigens are viruses. Vasculitis is the basic disease process in a number of disorders, including polyarteritis nodosa, erythema nodosum, Henoch–Schönlein purpura, serum sickness, temporal arteritis, and Buerger’s disease.