Papulonecrotic tuberculid is an eruption of necrotizing papules, particularly affecting the exetremities and occurring in more or less symmetrical crops, and responding to antituberculosis therapy. Individual lesions heal with scarring.
Histologically, vascular involvement is seen in early lesions. Late lesions are divided into two forms. In superficial forms, wedge shaped area of necrosis forms in epidermis and upper dermis. Epithelial and lymphoid cells gather around its
periphery.
In deep forms, with no epidermal change, granulomatous changes surrounded by well defined palisading histiocyte and lymphoid, epithelioid cells are seen. In mid-dermis and perivascular area, vessel showes vasculitis. In the first case,
leukocytoclastic
vasculitis and early granuloma formation were seen. In the second case, palisading granuloma formation was seen. In the third case, tuberculoid granuloma formation was seen.
We report three cases of papulonecrotic tuberculid showing three different stages of histological finding in individual cases.
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