There are 5 clinically distinct variants of porokeratosis, including classic porokeratosis of Mibelli, disseminated superficial (actinic) porokeratosis, linear porokeratosis, punctate porokeratosis, and porokeratosis palmaris et plantaris disseminate. Porokeratosis ptychotropica (PP) is the sixth, lesser-known variant of the spectrum. PP is characterized by verrucous plaques, often resembling psoriasis plaques, that affect the buttocks, most commonly the gluteal cleft, and can also involve the extremities, most commonly the lower legs and feet. Due to its characteristic verrucous appearance, designations such as verrucous or hyperkeratotic porokeratosis are occasionally used. Besides its predilection for specific locations, PP also has a significant predilection for men versus women.
This rare variant of porokeratosis can mimic the morphology and symptomology of other diseases at first glance. Education about the presentation of porokeratosis ptychotropica and its addition to the list of commonly described variants can help mitigate its frequent misdiagnosis, reducing treatment failure and unnecessary testing
