Erosive Arthritis Resembling Osteomyelitis in Behcet's Disease.

Erosive arthritis in Behcet's disease (BD) is rare and confused with infectious diseases such as osteomyelitis. Clinical course and imaging may be similar in BD-related arthritis and osteomyelitis. A 48-year woman diagnosed with BD developed recurrent pain in both feet. Magnetic resonance imaging of her feet showed bony erosions and suggested osteomyelitis with myositis or septic arthritis, but the response to antibiotics was equivocal. We diagnosed BD-related arthritis and started treatment with methotrexate, and increased azathioprine and sulfasalazine, and her joint symptoms improved. BD-related arthritis should be considered in the differential diagnosis of BD patients with articular manifestations that may mimic septic arthritis.