Papulonecrotic tuberculid (PNT) is an uncommon form of id eruption, which occurs in association with tuberculosis infections in patients with a high degree of immunity and allergic sensitivity to mycobacterial organisms. It commonly presents as recurrent crops of papulonecrotic lesions that crust or ulcerate, and heal with atrophic varioliform scars over time. The differential diagnoses of PTN are wide and varying. Tuberculin test is usually strongly positive. Histology shows tuberculoid histology with endarteritis and thrombosis of dermal blood vessels. One of the hallmarks of PNT is its prompt response to antituberculous therapy. The purpose of this article is to increase awareness of this condition among dermatologists.
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