Abstract

Introduction: Cutaneous tuberculosis (CTB) is a rare presentation of extrapulmonary tuberculosis (TB) with various clinical manifestations. Tuberculids, a type of CTB, are probably the result of hyperergic immune reaction induced by Mycobacterium tuberculosis. Lichen scrofulosorum (LS) is a rare tuberculid mostly seen in children and young adults with or without other manifestations of tuberculosis.

Case report: We present a 30 year old patient presented with a papular eruption on his trunk and upper extremities. The patient had recently started on a 4 drug-regimen treatment for a diagnosed tuberculous cervical lymphadenitis and he was under investigation for pulmonary TB. Histopathology of the papular lesions showed epithelioid granulomas strongly indicating lichen scrofulosorum. The eruption responded to antitubercular therapy with complete clearance of the lesions.

Discussion: The tuberculids are a form of CTB caused by hypersensitivity reactions to Mycobacterium tuberculosis. The diagnosis of LS is problematic and frequently delayed because of its rarity and clinical similarity to many other more common skin conditions.