title: Treatment of Porokeratosis: A Systematic Review.
abstract: BACKGROUND
  Porokeratosis (PK) is a rare skin disease of unknown etiology. It consists of a keratinization disorder, which may appear in several clinical forms and can undergo malignant transformation. The histopathological hallmark of PK is the cornoid lamella. While many topical, systemic, and surgical treatment modalities for PK have been described, no randomized controlled trials have been performed yet. Because of a lack of treatment standards for PK, European and international guidelines cannot be created.
  
  
  OBJECTIVE
  The aim of this systematic review is to outline options for treating PK.
  
  
  METHODS
  We performed a systematic literature search in an electronic database for published literature. A total of 88 articles fulfilling our inclusion criteria were found.
  
  
  RESULTS
  There were no randomized controlled trials on the treatment of PK, but mainly case reports and case series. Porokeratosis of Mibelli showed the best outcomes after treatment with imiquimod cream and linear PK responded well to topical or systemic retinoids. Topical vitamin D acid derivatives may be the best therapeutic option for disseminated PK. Surgical interventions and cryotherapy may be preferred in areas where the use of topical agents is difficult or contraindicated.
  
  
  CONCLUSIONS
  To offer patients with PK an evidence-based high-quality standardized therapy, randomized controlled trials are needed.
authors.affiliation: Department of Dermatology, University Hospital Jena, Erfurter Straße 35, 07743, Jena, Germany. till.weidner@med.uni-jena.de.
authors.forename: Till
authors.identifier: http://orcid.org/0000-0001-6064-851X
authors.initials: T
authors.lastname: Weidner
authors.affiliation: Department of Dermatology, University Hospital Jena, Erfurter Straße 35, 07743, Jena, Germany.
authors.forename: Tanja
authors.initials: T
authors.lastname: Illing
authors.affiliation: Department of Dermatology, University Hospital Jena, Erfurter Straße 35, 07743, Jena, Germany.
authors.forename: Diana
authors.initials: D
authors.lastname: Miguel
authors.affiliation: Department of Dermatology, University Hospital Jena, Erfurter Straße 35, 07743, Jena, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Elsner
mesh_terms: D000279:Administration, Cutaneous; D000634:Aminoquinolines / Q000008:administration & dosage*; D003879:Dermatologic Agents / Q000008:administration & dosage*; D062109:Dermatologic Surgical Procedures / Q000379:methods; D004359:Drug Therapy, Combination; D019317:Evidence-Based Medicine; D006801:Humans; D000077271:Imiquimod; D015603:Keratinocytes / Q000473:pathology; D017499:Porokeratosis / Q000473:pathology / Q000628:therapy*; D012176:Retinoids / Q000008:administration & dosage*; D016896:Treatment Outcome
chemical_list: D000634:Aminoquinolines; D003879:Dermatologic Agents; D012176:Retinoids; D000077271:Imiquimod