title: Recalcitrant papules and plaques on perianal area and buttocks.
authors.affiliation: Department of Dermatology, Hospital Universitari Sagrat Cor, Universitat de Barcelona, Barcelona, Spain.
authors.forename: Helena
authors.initials: H
authors.lastname: Collgros
authors.affiliation: Department of Dermatology, Hospital Universitari Sagrat Cor, Universitat de Barcelona, Barcelona, Spain.
authors.forename: Maribel
authors.initials: M
authors.lastname: Iglesias-Sancho
authors.affiliation: Department of Dermatology, Hospital Universitari Sagrat Cor, Universitat de Barcelona, Barcelona, Spain.
authors.forename: Maria-Jose
authors.initials: MJ
authors.lastname: Aldunce-Soto
mesh_terms: D002081:Buttocks; D006801:Humans; D008297:Male; D008875:Middle Aged; D010502:Perineum; D017499:Porokeratosis / Q000473:pathology*