title: Observational retrospective study evaluating the effects of oral isotretinoin in keloids and hypertrophic scars.
abstract: BACKGROUND
  Acne vulgaris is a chronic inflammatory disease characterized by non-inflammatory and inflammatory lesions that can cause scarring. Oral isotretinoin is the current recommended treatment for moderate and severe cases; however, there are reports of possible influences on the healing process of the skin, leading to an increase in the risk for hypertrophic scars and keloids. This hypothesis, although unproven, represents a contraindication to the treatment of acne scars during the 6-12 months after the cessation of isotretinoin.
  
  
  OBJECTIVE
  The aim of this study was to investigate the prevalences of hypertrophic scars and keloids in acne patients treated with oral isotretinoin.
  
  
  METHODS
  Three data collection strategies were used: (i) clinical examination of patients with acne vulgaris, exposed or unexposed to oral isotretinoin, focusing on the occurrence of hypertrophic scars and/or keloids; (ii) telephone interviews of patients using oral isotretinoin to treat acne vulgaris on the occurrence or worsening of keloids; and (iii) clinical examination of patients with previous use of oral isotretinoin followed at a specific keloid treatment clinic.
  
  
  RESULTS
  The resulting data showed no differences in wound healing.
  
  
  CONCLUSIONS
  These findings may indicate that the occurrence of hypertrophic scars or keloids in patients using oral isotretinoin is an undesirable event arising from an individual response and may be related to inflammatory acne evolution.
authors.affiliation: Department of Dermatology, Universidade Federal de São Paulo (UNIFESP; Federal University of São Paulo), São Paulo, SP, Brazil.
authors.forename: Lilia R S
authors.initials: LR
authors.lastname: Guadanhim
authors.affiliation: Department of Dermatology, Universidade Federal de São Paulo (UNIFESP; Federal University of São Paulo), São Paulo, SP, Brazil.
authors.forename: Rubens G
authors.initials: RG
authors.lastname: Gonçalves
authors.affiliation: Department of Dermatology, Universidade Federal de São Paulo (UNIFESP; Federal University of São Paulo), São Paulo, SP, Brazil. edileia_bagatin@yahoo.com.br.
authors.forename: Ediléia
authors.initials: E
authors.lastname: Bagatin
mesh_terms: D000152:Acne Vulgaris / Q000188:drug therapy; D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D017439:Cicatrix, Hypertrophic / Q000139:chemically induced / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D003879:Dermatologic Agents / Q000008:administration & dosage* / Q000009:adverse effects; D018450:Disease Progression; D005260:Female; D006801:Humans; D015474:Isotretinoin / Q000008:administration & dosage* / Q000009:adverse effects; D007627:Keloid / Q000139:chemically induced / Q000453:epidemiology*; D008297:Male; D015995:Prevalence; D012189:Retrospective Studies; D014945:Wound Healing / Q000187:drug effects; D014947:Wounds and Injuries / Q000150:complications; D055815:Young Adult
chemical_list: D003879:Dermatologic Agents; D015474:Isotretinoin
keywords: acne; hypertrophic scar; keloid; oral isotretinoin; retinoids; wound healing