Sarcoidosis and spondylarthropathy. Three case-reports

Coexistent sarcoidosis and seronegative spondylarthropathy have rarely been reported. We add three new cases to the nine previously published. Two men and one woman with sarcoidosis met Amor's criteria for spondylarthropathy. The diagnosis of sarcoidosis was based on histologic findings in two cases and on roentgenographic and laboratory test findings in one case. The features of each of the two diseases were unremarkable. The two diagnoses were confirmed at about the same time. Osteoarticular manifestations of sarcoidosis are reviewed. Our case-reports illustrate the diagnostic difficulties raised by discovery of sacroiliitis in a patient with sarcoidosis: sarcoid osteitis, infection, or a spondyloarthropathy can be the cause of the sacroiliac lesions. Moreover, the pelvic and spinal manifestations of sarcoidosis can mimick a spondylarthropathy. Coexistence of sarcoidosis and spondylarthropathy is probably due to chance, since there are no shared predisposing genetic factors and the number of reported cases is small.