Chronic violaceous plaques on the arm.

A 45-year-old man from Pakistan presented with two raised and nodular plaques on his left arm that had been present since birth. He habitually scratched the lesions. The patient had no relevant medical history and denied contact with animals or recent travel. Biopsies revealed granulomatous inflammation, and further testing confirmed the presence of Mycobacterium tuberculosis (Mtb). The patient received antituberculosis therapy, leading to significant improvement in the skin lesions. This case highlights the importance of considering cutaneous Mtb in cases of chronic lesions with non-necrotizing granulomas and emphasizes the need for tissue culture to confirm the diagnosis and initiate prompt treatment. [Extracted from the article]