Porokeratosis is a rare skin disorder characterized by one or more annular plaques with a surrounding raised horny border that spreads centrifugally. Variants of porokeratosis have been described that differ in morphologic shapes, distribution, and clinical course (Schamroth et al., 1997). However, as noted by Sybert (2010), families with expression of more than one variant of porokeratosis among members, and individuals expressing more than one variant, have been reported, suggesting that the distinctions among these variants may be artificial.
Porokeratosis palmaris plantaris et disseminata (PPPD) is a subtype in which lesions initially develop on the palms and soles, but later involve other parts of the body, including the trunk and limbs (Wei et al., 2003).
For a discussion of genetic heterogeneity of porokeratosis, see 174800. [from
OMIM]