Mycobacterium marinum Infection of the Hand in an Immunocompromised Aquarium Hobbyist.

M. marinum, a nontuberculous mycobacterium, is a rare human pathogen widely distributed in the aquatic environment. In the previous century, epidemics took place due to inadequately chlorinated swimming pool water. Nowadays the majority of infections are acquired through contact of previously damaged skin with contaminated fish tank water. We present a case of M. marinum infection of the hand in an aquarium hobbyist which stayed unrecognized for 2 years. After confirming the correct diagnosis, the patient was successfully treated with a regiment containing clarithromycin and rifampicin. The aim of this paper is to raise the awareness of the possibility of M. marinum infection when encountered with non-healing nodular/verrucous/ulcerative lesions of the extremities.