Urethral cultures were negative for gonorrhea. Skin biopsy cultures were negative for bacterial and fungal pathogens. Synovial fluid from the right knee was noninflammatory and was negative for culture of bacterial and fungal pathogens. Differential Diagnosis 1. This patient presented with an inflammatory joint and bone process accompanied by acneiform rash and by systemic features including weight loss, high ESR, polyclonal gammopathy, and anemia.
Sarcoidosis causes both bone and skin disease.
Musculoskeletal presentations of sarcoidosis include acute arthritis and chronic lytic lesions in bones, particularly in the phalanges, due to replacement of bone by granulomas. Our patient had had several bone biopsies which did not show granulomas. Furthermore, Ankylosis of the SI joint and syndesmophytes would be highly atypical for sarcoidosis. Our patient was HLA-B27 negative, had never had uveitis, heel pain, or documented urethritis. His rash was not psoriatic and he had no family history of spondylitis.