Mycobacterium ulcer infection

Mycobacterium ulcerans infection is present throughout the world, mainly in tropical rain forest areas. The natural host and human transmission of this bacterium are unknown, and insects may be the transmission vector. Skin lesions are common in the forearms and lower legs. At first, it is a solid and painless subcutaneous nodule. After ulceration, a necrotic ulcer is formed. The edge is slowly enlarged with chiseling. The surrounding skin is bulged with infiltration and pigmentation. The surface is dry. The bottom of the ulcer is an adhesive gray pseudomembrane. Superficial, individual deep into the periosteum. It can be divided into pre-ulcer stage (early stage), ulcer stage, and post-ulcer stage. Histopathology is different. The diagnosis requires culture and animal inoculation. Systemic treatment of clofazimine is effective,