Lichen Scrofulosorum Without Mantoux Positivity in a 72-Year-Old Male: A Clinical Paradox

Lichen scrofulosorum (LS) represents a cutaneous hypersensitivity reaction to Mycobacterium tuberculosis (MTB) in individuals with preserved cell-mediated immunity. It typically presents as asymptomatic, monomorphic papules, predominantly distributed over the trunk, and demonstrates a prompt response to anti-tubercular pharmacotherapy. While the Mantoux test is usually strongly positive, this case highlights the atypical occurrence of Mantoux negativity in a 72-year-old patient, an age group in which LS is rarely encountered. This case emphasizes the need for a comprehensive diagnostic workup, including histopathological analysis and other relevant investigations, when the Mantoux test yields an unexpected result. A keen clinical eye and strong diagnostic suspicion are essential to identifying LS in the context of such atypical features.