Fish tank granuloma in a 14-month-old girl.

A 14-month-old girl developed a persistent ulcerated nodule on her right lower leg associated with further nodules along the thigh. A clinical diagnosis of fish tank granuloma was suspected because of tropical fish tanks at home. The diagnosis was confirmed when Mycobacterium marinum was isolated from low-temperature culture of skin tissue. The child made a complete recovery following treatment with rifampicin for 6 months despite in vitro sensitivity tests reporting resistance. M. marinum infection is uncommon in children, but the diagnosis should be considered in children presenting with chronic skin lesions spreading in a sporotrichoid pattern.