title: A case of linear porokeratosis superimposed on disseminated superficial actinic porokeratosis.
abstract: We present a female patient with linear porokeratosis of her right arm since childhood. At the age of 67 years she additionally developed disseminated superficial actinic porokeratosis (DSAP) involving both lower legs. This uncommon coexistence of two different types of porokeratosis fulfils the clinical criteria of a type 2 segmental manifestation of an autosomal dominant skin disorder, being superimposed on the ordinary nonsegmental lesions and reflecting loss of heterozygosity that occurred at an early developmental stage. In DSAP molecular evidence of this concept is so far lacking, but such proof has already been provided in several other autosomal dominant skin disorders. Molecular analysis of cases of type 2 segmental involvement may help elucidate the genetic defect causing DSAP.
authors.affiliation: Department of Dermatology, University of Cologne, Cologne, Germany.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Löhrer
authors.forename: Aysegül
authors.initials: A
authors.lastname: Neumann-Acikel
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Eming
authors.forename: Karin
authors.initials: K
authors.lastname: Hartmann
authors.forename: Heinrich
authors.initials: H
authors.lastname: Rasokat
authors.forename: Thomas
authors.initials: T
authors.lastname: Krieg
authors.forename: Rudolf
authors.initials: R
authors.lastname: Happle
authors.forename: Sabine
authors.initials: S
authors.lastname: Eming