Sarcoidosis: clinical manifestations, epidemiology, therapy, and pathophysiology.

Sarcoidosis is an idiopathic granulomatous disease involving one or more multiple organ systems, characterized by the histologic finding of noncaseating epithelioid cell granulomas. The disease has a predilection for intrathoracic structures; the musculoskeletal system is less frequently involved. Most osseous lesions in sarcoidosis are visible in the small joints of the hands and feet. Articular disease may present as an acute or chronic polyarthritis. Muscle involvement in sarcoidosis is generally asymptomatic. Neurologic findings of the central and peripheral nervous systems may occur in sarcoidosis. Subcutaneous nodules are of diagnostic value. Sarcoid vasculitis may involve small and large blood vessels. Sarcoidosis of the exocrine glands may mimic Sjögren's syndrome. Spontaneous remission of disease often occurs. Treatment with nonsteroidal anti-inflammatory agents, corticosteroids, antimalarials, radiation therapy, and immune-modulating drugs may be beneficial in the treatment of sarcoidosis.