Considering Mycobacterium haemophilum in the differential diagnosis for lytic bone lesions in AIDS patients who present with ulcerating skin lesions.

Mycobacterium haemophilum has recently been recognized as a newly emerging cause of osteomyelitis in immunocompromised patients. While still uncommon, its incidence has increased significantly with the growing AIDS epidemic. Like its relative M. tuberculosis and M. intracellulare, this organism is acid-fast positive; yet unlike its more well-known counterparts, M. haemophilum requires iron-supplemented culture media and low incubation temperatures (30-32 degrees C) for growth. We describe a case of M. haemophilum osteomyelities in the distal femur of a 36-year-old HIV-positive male, who also presented with multiple skin ulcerations. In an AIDS patient with a lytic bone lesion and concomitant skin eruptions, the diagnosis of M. haemophilum should be entertained so that special culture media can be used and appropriate treatment administered.