Porokeratosis ptychotropica: A rare variant often misdiagnosed

Porokeratosis ptychotropica is a rare and often misdiagnosed variant of porokeratosis, characterized by annular plaques with keratotic ridges typically found in skin folds. This report describes the first documented case in Bangladesh of a 39-year-old man who presented with a severely itchy, well-demarcated, erythematous plaque with a distinctive butterfly-like appearance on his natal cleft, presenting for 18 years. Histological examination confirmed the diagnosis, revealing hyperkeratosis, acanthosis, and characteristic coronoid lamellae. The patient showed significant improvement following cryotherapy and topical imiquimod treatment. This case underscores the diagnostic challenges posed by porokeratosis ptychotropica due to its clinical similarities to other conditions. Early diagnosis is crucial to minimize patient suffering and mitigate the risk of malignant transformation. Cryotherapy may be considered an effective treatment option for this rare condition.