[A case of complicated Mycobacterium marinum infection - "nihil nocere" in differential diagnostic and therapy]

A 50-year-old patient presented to his family doctor with pain and livid, subcutaneous nodules on the right hand.Laboratory chemistry and native radiologic examinations were unremarkable. An attempt at NSAID therapy was unsuccessful. On the basis of the clinical picture, immunomodulating therapy was carried out on suspicion of rheumatoid arthritis.Due to significant clinical worsening, hand surgery was needed and MM was detected by biopsy.Combination antimycobacterial therapy was initiated. Four months later, visual disturbances and polyneuropathy occurred. The cause was a supratherapeutic dose of ethambutol. After a change in therapy had been carried out, almost a complete regression of symptoms could be achieved.Infectious diseases with a low local prevalence, for example caused by non-tuberculous mycobacteria, and their therapeutic management should be left to treatment centers with a high level of infectiological expertise. When treating unselected patients with unclear skin lesions, the question of aquarium exposure should be raised.