[Mycobacterium ulcerans infection].

Mycobacterium ulcerans infection, or Buruli ulcer, is the third most common mycobacterial disease of the immunocompetent host in the tropical areas. M. ulcerans reservoir is aquatic. Infection occurs in children and young adults. The lesion begins with an indolent subcutaneous nodule, principally located on the limbs, that progressively changes into a deep indolent extensive ulcer. M. ulcerans produces a lipidic necrotic and immunosuppressive toxin, named mycolactone, that causes the clinical lesions. In endemic areas, clinical diagnosis is confirmed by microscopic examination. Spontaneous healing occurs after several months or years, causing retractile scars. Surgical excision and grafting is the treatment of choice. Antibiotic therapy is of limited value.