Infection of the skin by Mycobacterium marinum: report of five cases.

Five patients 6 to 47 years of age had bacteriologically confirmed Mycobacterium marinum infections of the skin. In four patients the initial lesions were chancriform and were on a finger or a hand; ascending lymphadenitis followed. The other patient had nodular inflammatory lesions on one cheek. Biopsies were performed in four patients; all specimens showed a granuloma, and acid-fast bacilli were identified in one of the four. Four of the five patients were untreated; the fifth was given antituberculous drugs. In all five patients the condition was chronic, with progressive resolution of the lesions during follow-up periods of 1 to 6 years. M. marinum infections of the skin are rare in Canada. This may be due in part of lack of clinical awareness or failure to identify the organism. Biopsy specimens should be obtained under sterile conditions and nondigested material should be inoculated into the footpads of mice.