Infliximab is one of the TNF-α inhibitors, a class of medications that made a revolution in treatment of rheumatic diseases especially rheumatoid arthritis. The activation of tuberculosis and atypical mycobacterial infections has been described in the setting of TNF-α inhibitor therapy, but septic arthritis relating to this treatment has not yet been reported in previous literature. We describe a 50-year-old woman with dermatomyositis who developed Mycobacterium Avium Complex septic arthritis, while being treated with infliximab for active skin disease. This case highlights an important complication related to therapy with TNF-α inhibitors.
