Mycobacterial Skin Infections

Mycobacterial skin infections are important to recognize in the paediatric population as they can cause serious morbidity. They include tuberculosis, leprosy and various nontuberculous mycobacterial infections. Of these, both tuberculosis and leprosy have caused a heavy disease burden among children, especially in developing countries, owing to several factors such as malnutrition, poverty, poor living conditions and emerging human immunodeficiency virus (HIV) infection. Cutaneous tuberculosis, mostly caused by Mycobacterium tuberculosis, can have varied clinical manifestations depending on the host immune response. Children usually acquire the infection from infected adults. Skin tuberculosis in children can be severe with a protracted course. Multifocal and disseminated lesions are quite common in children compared to adults. Systemic infection is also frequent in children. Several unusual patterns of skin tuberculosis are recognized in the paediatric population. Leprosy in children is still prevalent (>100 cases a year are reported) in some of the African countries, the Dominican Republic, the eastern Mediterranean and the western Pacific region, especially Micronesia. Borderline tuberculoid leprosy and indeterminate leprosy are the two common forms seen in children and the lesions are usually macular. Nontuberculous mycobacterial infections are related to environmental bacteria. The incidence of these infections is increasing, especially in tropical climates. They cause several clinical syndromes such as cervical lymphadenopathy, skin and soft tissue infections following injury and systemic diseases.