[Tuberculous arthritis--a rare, but important differential diagnosis in juvenile chronic arthritis].

We observed a 13 year old Turkish boy suffering from chronic arthritis of the left knee since 1983. Clinical symptoms as slow progression of the disease and laboratory data including a positive HLA B 27 test suggests the diagnosis of juvenile chronic arthritis. A tuberculous arthritis was initially excluded by X-ray examination of the chest. The positive tuberculin test was attributed to the BCG vaccination. Because of insufficient response to antiinflammatory drug therapy a synovectomy was performed for diagnostic as well as therapeutic reasons. Histopathological results suggested sarcoidosis. A second synovial biopsy of the affected joint revealed granulomas combined with multiple necrosis typical for tuberculous infection. The animal experiments showed positive results. Tuberculostatic therapy was successful with INH, myambutol and rifampicin. Joint function and MRI results markedly improved.