You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is An 8-year-old boy presents with well defined annular lesion over the buttock with central scarring that is gradually progressive over the last 8 months. The diagnosis is and explain in detail?
B i.e. Lupus vulgarisAnnular plaque with central scarring - Typically seen in Lupus vulgaris.Most common sites in India = Buttocks and face.Cause:The underlying focus of TB (bone, joint or lymph node).Contiguous extension of disease from underlying affected tissue.By hematogenous or lymphatic spread.Arise after exogenous inoculation.A complication of BCG vaccination.Features & manifestations:Cutaneous TB more commonly affects buttocks & extremities rather than the face.Such a pattern is usually due to reinoculation and may relate to playing without clothing or shoes.Lesions:Becomes flat plaques with a serpiginous or polycyclic outline & a smooth surface or psoriasiform scaling: there may be erosions, ulceration, and scarring.Hyperophic forms appear as a soft mass with a nodular, hyperkeratotic surface.