[Buruli ulcer. A mycobacterial skin disease].

Buruli ulcer is a chronic ulcerative skin disease caused by Mycobacterium ulcerans. It is the third most common mycobacterial disease in immunocompetent people and affects mainly children living in humid areas of the tropical rain forest. The mode of transmission is unknown. The microorganisms penetrate the skin via microinjuries. A few weeks after infection, a subcutaneous nodule develops, followed by necrosis of the subcutaneous fat and finally by a large dermal ulceration. Typical is the lack of an acute inflammatory response, likely due to an immunosuppressive toxin produced by M. ulcerans called mycolactone. The lesions mostly affect the limbs. Constitutional symptoms are normally absent. The only effective treatment consists of wide excision, often followed by skin grafts. Conservative measures are rarely successful. Buruli ulcer is characterized by low mortality and high morbidity. Early recognition and treatment are decisive for the complete cure and prevention of debilitating deformities.