title: Late onset pityriasis rubra pilaris type IV treated with low-dose acitretin.
abstract: Pityriasis rubra pilaris is a chronic inflammatory dermatosis of unknown etiology and great clinical variability. It has been divided into six categories. Types III, IV, and V occur in childhood and are distinguished by their clinical presentation, age of onset, and course. We report a 19-year-old male patient with a 2-week history of pruritic, scaling dermatosis of the hands, feet, elbows, and knees. He had no family history of skin disease. On physical examination, we observed circumscribed, reddish-orange, scaling plaques affecting the elbows and knees and a waxy palmoplantar keratoderma. The skin biopsy showed acanthosis, alternating orthokeratosis, parakeratosis, and follicular plugging suggestive of pityriasis rubra pilaris. The patient started treatment with oral acitretin, 25 mg every other day. The treatment was tolerated well, and after 6 months the lesions had resolved completely. Pityriasis rubra pilaris is a chronic papulosquamous disorder of unknown pathogenesis, characterized by reddish-orange scaly plaques, palmoplantar keratoderma, and keratotic follicular papules. There is still no consensus regarding the treatment, but therapeutic options include systemic retinoids, particularly acitretin in the recommended dose of 0.5 to 0.75 mg/kg/day. In our case, the patient was treated with a low-dose regimen of acitretin, which was effective and well tolerated.
authors.affiliation: Department of Dermatology, Porto Central Hospital, Porto, Portugal.
authors.forename: Fernando
authors.initials: F
authors.lastname: Mota
authors.affiliation: Department of Dermatology, Porto Central Hospital, Porto, Portugal.
authors.forename: Sandrina
authors.initials: S
authors.lastname: Carvalho
authors.affiliation: Department of Dermatology, Porto Central Hospital, Porto, Portugal.
authors.forename: Madalena
authors.initials: M
authors.lastname: Sanches
authors.affiliation: Department of Dermatology, Porto Central Hospital, Porto, Portugal.|Dermatology Research Unit, Porto Central Hospital, Porto, Portugal.|Abel Salazar Biomedical Sciences Institute, University of Porto, Porto, Portugal.
authors.forename: Manuela
authors.initials: M
authors.lastname: Selores
mesh_terms: D017255:Acitretin / Q000627:therapeutic use*; D006801:Humans; D007641:Keratolytic Agents / Q000627:therapeutic use*; D008297:Male; D010916:Pityriasis Rubra Pilaris / Q000188:drug therapy* / Q000473:pathology; D055815:Young Adult
chemical_list: D007641:Keratolytic Agents; D017255:Acitretin