Cutaneous lesion due to Mycobacterium fortuitum

Nontuberculous mycobacteria usually cause systemic disease and often appear as a primary pulmonary infection. However, a cutaneous lesion may be the first or only sign of infection. The most frequent human diseases caused by Mycobacterium fortuitum are cutaneous or soft tissue infections, usually preceded by injection, trauma or surgery. We report a case of a cutaneous lesion due to Mycobacterium (M.) fortuitum occuring in a 50-year-old man with a subcutaneous flat nodule on his left anterior tibia. He had received a small injury to his left shin in a swimming pool. The culture from the skin biopsy specimen on Lowenstein-Jensen medium yielded colonies after 5 days. The microorganism was subsequently identified as M. fortuitum by selected biochemical reactions. Therapy was instituted with minocycline for 5 months.