Introduction Demographics Causes Clinical features Complications Diagnosis Differential diagnoses Treatment Outcome
Porokeratosis refers to a group of disorders characterised by abnormal keratinisation.
Porokeratosis ptychotropica is a rare form of porokeratosis that was first described in 1995. It presents as scaly or warty patches on the buttocks [1].
Men are nine times more affected by porokeratosis ptychotropica than women, and the average age of onset is 46.7 years (the reported age range is 27–84 years) [2].
The exact cause of porokeratosis ptychotropica is not known [3]. Other forms of porokeratosis have been associated with risk factors such as exposure to ultraviolet radiation, trauma, renal and liver failure, organ transplantation, and immune suppression [4].
With other variants of porokeratosis, a genetic predisposition has been described; however, no genetic predisposition is known for porokeratosis ptychotropica, possibly due to its rareness [2].
Porokeratosis ptychotropica presents as warty or scaly plaques on the buttocks.
Porokeratosis ptychotropica can be difficult to diagnose, leading to a delay in treatment [2].
The diagnosis of porokeratosis ptychotropica most often requires a biopsy. The pathology is very distinct for this condition, showing the classic cornoid lamella.
The differential diagnosis of porokeratosis ptychotropica includes:
There is no known cure for porokeratosis ptychotropica, and the results of treatment are generally disappointing. The appearance may improve with the following measures:
Porokeratosis ptychotropica tends to persist. In other forms of porokeratosis, there is a small risk of transformation to skin cancer. Regular follow-up of such skin lesions is recommended [2].
