RESUMO
Rheumatoid arthritis was diagnosed in a 30-year-old woman with erythema nodosum and arthritic symptoms since 1994, and she was treated with anti-rheumatic agents. Mediastinal and bilateral hilar lymphadenopathy and abnormal pulmonary shadows were detected in 1996, and she was admitted to our hospital in 1997. We also recognized the elevation of ACE and lysozyme, and found granulomas in a transbronchial lung biopsy and an arthrosis synovia biopsy. From these findings, sarcoidosis was diagnosed. Sarcoidosis demonstrating erythema nodosum, arthritis, and bilateral hilar lymphadenopathy is called Löfgren's syndrome. In Caucasians, Löfgren's syndrome is frequently encountered, but it is rare in Japanese. Our case had coexisting arthrosis symptoms, and satisfied the diagnosis criteria of rheumatic arthritis. Therefore, the differential diagnosis was important. We emphasize that it is necessary to consider Löfgren's syndrome when diagnosing patients with rheumatic features, even in Japan.