ABSTRACT
Leprosy, also known as Hansen’s disease, is a chronic granulomatous disease caused by Mycobacterium leprae that typically affects the skin, mucous membranes, peripheral nervous system, eyes and testes. The main clinical subtypes of leprosy include indeterminate, tuberculoid, borderline tuberculoid, borderline borderline, borderline lepromatous and lepromatous leprosy; lepra bonita and histoid leprosy are rarer forms. Lupus vulgaris and tuberculosis verrucosa cutis are the most frequent clinical variants of cutaneous tuberculosis, a skin infection mainly caused by Mycobacterium tuberculosis. The former results from a reinfection by exogenous inoculation or internal spread, whereas the latter is a primary infection due to a direct inoculation into the skin. The dermoscopic pattern of lupus vulgaris is similar to that of other granulomatous dermatoses, being mainly characterized by focal or diffuse orange-yellow structureless areas histologically corresponding to dermal granulomas.
