Sarcoidosis acutely involving the musculoskeletal system.

A 69-year-old man complained of knee pain, subsequent polyarthralgia, and pains of the muscles of the pelvic girdle and thighs. At the same time, erythema of the face and hands appeared. Biopsy of the skin and muscle revealed non-caseating granuloma of epithelioid cells. The level of serum angiotensin-converting enzyme was normal, but that of lysozyme was elevated. Chest X-ray and CT did not show bilateral hilar lymphadenopathy (BHL) but revealed infiltrative ground glass appearance-like shadows of both lungs, and a Ga scintigram disclosed accumulation in the right hilar region, but not in the muscles. These complaints were quickly ameliorated by the administration of prednisolone. The present patient represented a rare case of acute musculoskeletal system involvement in sarcoidosis not typical of Löfgren's syndrome.