Porokeratosis ptychotropica: a rare and evolving variant of porokeratosis.

Porokeratosis ptychotropica represents a rare and under-recognized variant of porokeratosis. There are also alternative descriptions for this disorder in the literature. Since its original description in 1995, additional characteristic features have been showed in case reports published in the literature. These cumulative reports, although still limited in numbers, have helped to further shape and define this entity. A case report and review of published literature on this unusual entity are presented. The specific combination of clinical, morphological and histopathological characteristics that can facilitate recognition of the disorder is discussed. There has been a call for uniformity in terminology and a suggestion for alternative terminology has been made. However, we discuss why the earlier term, porokeratosis ptychotropica, is still preferred.