[Mycobacterium marinum. A rare cause of infection of the skin and joints].

Mycobacterium marinum is a rare cause of disseminated infection in man. The case report describes an 80-year-old woman, who had been treated with oral corticosteroids for bronchial asthma for 40 years, and in the same period had been swimming daily in swimming pools. At the first admission, the symptoms and clinical findings were interpreted as seronegative rheumatoid arthritis. After eight years of disease with recurrent infections of the skin, periarticular tissues and joints in the hands and one elbow, a biopsy specimen from an abscess showed granulomatous inflammation and acid fast bacilli. Culture for mycobacteria grew M. marinum. There was a severe, destructive monoarthritis in the right second metacarpophalangeal joint. The patient recovered completely on treatment with clarithromycin and doxycycline.