Septic arthritis associated with mycobacterium avium: a case report and literature review

A 58 year old man, with systemic lupus erythematosus, developed septic arthritis due to an atypical mycobacterium, M. avium. The patient's course, as well as 46 cases reviewed from the literature, illustrates the insidious nature of atypical mycobacterial infections. Septic arthritis or peri-arthritis was generally not suspected at initial evaluation, leading or at least 40% of patients receiving intra-articular steroids for non-specific reasons. A diagnosis was eventually obtained in 85% of cases by surgical biopsy and culture. In only15% was a diagnosis made by culture of synovial or bursal fluid. The relative in vitro resistance of "atypicals" to antituberculous drugs and the frequent necessity for surgery to make a diagnosis, led to surgery consituting partial or total therapy in 89% of cases. Whether patients were treated with surgery alone, surgery plus antituberculous drugs, or antituberculous drugs alone, clinical improvement generally occured. Because most patients had limited follow-up and because atypical mycobacterial infections often relapse, none of the cases reviewed should be considered "cures", be but rather instances of clinically inactive disease.