Lichen Planus Pigmentosus Localized to the Glans Penis: A Rare Presentation Treated With Ruxolitinib

Lichen planus pigmentosus (LPP) is a rare variant of lichen planus characterized by macules of black or dark brown color distributed in the sun-exposed areas of the body. It is common among individuals with darker skin, with cases reported in the Middle East, Korea, Japan, and Latin America. Genital involvement is rare, with no reported cases describing isolated penile disease. Management of genital LPP is also challenging due to the sensitive nature of the skin and the associated risks of long-term topical corticosteroid use. We report a case of a 24-year-old male presenting with asymptomatic hyperpigmented lesions localized to the dorsal penile shaft, diagnosed as LPP on histopathology. The patient demonstrated minimal response to prior therapies, including topical corticosteroids and topical calcineurin inhibitors (TCIs). Given treatment resistance, topical ruxolitinib was initiated, with subtle improvement. This case highlights a rare anatomic presentation of LPP and explores the potential role of topical JAK inhibitors as a novel therapeutic option for lichen-planus-associated pigmentary disorders.