title: Keratoacanthomas arising in association with prurigo nodules in pruritic, actinically damaged skin.
abstract: BACKGROUND
  There is no known association between the development of keratoacanthomas and prurigo nodules.
  
  
  OBJECTIVE
  We report a case series of 7 patients with a long-standing history of actinic damage, pruritus, and prurigo nodularis who developed widespread keratoacanthomas within the same affected area.
  
  
  METHODS
  This was a retrospective case series assessing the clinical characteristics of patients with multiple keratoacanthomas arising in association with prurigo nodules.
  
  
  RESULTS
  All 7 patients were elderly Caucasian women (mean age 79 ± 3.7 years) with actinically damaged skin and a long-standing history of widespread pruritus and prurigo nodules. All patients had histologically confirmed keratoacanthomas, or squamous cell carcinomas with the clinical appearance of a keratoacanthoma, that developed within the field of prurigo nodules. All 7 patients had a clinical response to acitretin with a decrease in the number of lesions. Four patients had an associated eczematous dermatitis and were also treated with cyclosporine with improvement in pruritus and prurigo nodules and no increase in keratoacanthomas.
  
  
  CONCLUSIONS
  The retrospective design and small number of patients are limitations to this study.
  
  
  CONCLUSIONS
  Our case series represents a distinct subset of elderly individuals with extensive actinic damage who we believe are predisposed to developing both prurigo nodules and keratoacanthomas.
authors.affiliation: Ronald O. Perelman Department of Dermatology, New York University School of Medicine, New York, New York 10016, USA.
authors.forename: Timothy P
authors.initials: TP
authors.lastname: Wu
authors.forename: Kristen
authors.initials: K
authors.lastname: Miller
authors.forename: David E
authors.initials: DE
authors.lastname: Cohen
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Stein
mesh_terms: D017255:Acitretin / Q000627:therapeutic use; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use; D002294:Carcinoma, Squamous Cell / Q000150:complications* / Q000628:therapy; D017679:Cryotherapy; D016572:Cyclosporine / Q000627:therapeutic use; D003879:Dermatologic Agents / Q000627:therapeutic use; D004485:Eczema / Q000150:complications / Q000188:drug therapy; D005260:Female; D006801:Humans; D007636:Keratoacanthoma / Q000150:complications* / Q000473:pathology / Q000628:therapy; D007641:Keratolytic Agents / Q000627:therapeutic use; D055623:Keratosis, Actinic / Q000150:complications*; D011536:Prurigo / Q000150:complications* / Q000628:therapy; D011537:Pruritus / Q000150:complications; D012189:Retrospective Studies
chemical_list: D000970:Antineoplastic Agents; D003879:Dermatologic Agents; D007641:Keratolytic Agents; D016572:Cyclosporine; D017255:Acitretin
keywords: acitretin; cyclosporine; eczematous dermatitis; keratoacanthoma; pathogenesis; prurigo nodularis; prurigo nodule