Eight members from four generations of a family had multiple superficial porokeratoses on the trunk, palms, and soles. This appears to be a third type of porokeratosis, distinct from the classic Mibelli type or the Chernosky disseminated superficial actinic porokeratosis (DSAP) type. The disease begins in the late teens and early twenties, is transmitted as an autosomal dominant, and affects males twice as often as females. The hallmark of this disease is the early appearance of plantar and palmar lesions with subsequent involvement of other areas of the body including surfaces not exposed to ultraviolet radiation. Morphologically the clinical lesions resemble Chernosky's DSAP. Histologically it has the identifying features of porokeratosis with a cornoid lamella. One of our eight patients developed squamous cell carcinomas in areas of porokeratosis. No effective mode of therapy has been found.
Guss SB, Osbourn RA, Lutzner MA. Porokeratosis Plantaris, Palmaris, et DisseminataA Third Type of Porokeratosis. Arch Dermatol. 1971;104(4):366-373. doi:10.1001/archderm.1971.04000220024005