Sarcoidosis.

More than a century ago, Jonathan Hutchingson, a surgeon-dermatologist, identified the first case of sarcoidosis at King's College, London. The disease is now known as a commonplace multisystem disorder characterized by the formation of noncaseating granulomata. The diagnosis of sarcoidosis is established by recognizing clinicoradiologic findings and providing histologic evidence of non-caseating granuloma. Serum angiotensin converting enzyme levels are high in about two thirds of the patients and hypercalcemia is a feature in one of every ten victims of sarcoidosis. Immunologic abnormalities include depression of cutaneous delayed-type hypersensitivity, accumulation of T-cells at the site of activity, hyperactive B-cells, and the presence of circulating immune complexes. The course and prognosis of the disease usually correlate with the mode of onset. An acute onset with erythema nodosum indicates a good prognosis and spontaneous resolution; whereas, an insidious onset may be followed by relentless, progressive fibrosis. Mortality and morbidity are caused by pulmonary fibrosis, cardiac arrhythmias, renal failure, neurologic involvement, and blindness. Corticosteroids and chloroquine relieve symptoms and suppress inflammation and granuloma formation.