Porokeratosis punctata palmaris et plantaris. A new entity?

Seven members from three generations of a Saudi family presented with porokeratosis punctata palmaris et plantaris (PPPP). In our series of patients, the disorder began in their early 20s, seemed to be transmitted as a dominant trait, and affected males only. The elementary lesion was a tiny keratotic spine, and the involvement was strictly limited to the volar aspects of the hands and to the soles of the feet. Histological studies showed a columnar parakeratosis that resembled the cornoid lamella of porokeratosis, but other clinical and histological traits tended to make PPPP an entity that was distinct from true porokeratosis. There have been only six reports in the literature on genuine PPPP before this series.