title: Analysis of erythema after Er:YAG laser skin resurfacing.
abstract: BACKGROUND
  Postoperative erythema can be expected to occur in every patient after laser resurfacing, and pigmentary disturbances may be related to the intensity and the duration of erythema.
  
  
  OBJECTIVE
  This study was undertaken to assess the clinical features of erythema, the factors that influence its duration, and the relation between the duration of erythema and the incidence of hyperpigmentation and hypopigmentation in skin of Asian persons after Er:YAG laser resurfacing.
  
  
  METHODS
  A total of 218 patients (skin phototypes III to V) were recruited and treated with a short-pulsed Er:YAG laser, a variable-pulsed Er:YAG laser, or a dual-mode Er:YAG laser for skin resurfacing. Clinical assessments were performed retrospectively using medical charts and serial photographs.
  
  
  RESULTS
  Postoperative erythema was observed in all patients after Er:YAG laser resurfacing with a mean duration of 4.72 months. In 98.2% of patients, erythema faded completely within 12 months. Postinflammatory hyperpigmentation was observed in 38.1% of patients after Er:YAG laser resurfacing.
  
  
  CONCLUSIONS
  Skin phototype, level of ablation, and depth of thermal damage caused by a long-pulsed laser appear to be important factors that affect the duration of erythema. Moreover, prolonged erythema was related to the risk of postinflammatory hyperpigmentation.
authors.affiliation: Department of Dermatology, Korea University Anam Hospital, Seoul, Korea.
authors.forename: Na Young
authors.initials: NY
authors.lastname: Ko
authors.forename: Hyo-Hyun
authors.initials: HH
authors.lastname: Ahn
authors.forename: Soo-Nam
authors.initials: SN
authors.lastname: Kim
authors.forename: Young-Chul
authors.initials: YC
authors.lastname: Kye
mesh_terms: D000328:Adult; D044466:Asian People; D062109:Dermatologic Surgical Procedures; D004890:Erythema / Q000145:classification* / Q000209:etiology*; D005260:Female; D006801:Humans; D017495:Hyperpigmentation / Q000209:etiology; D017496:Hypopigmentation / Q000209:etiology; D053844:Lasers, Solid-State / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D019651:Plastic Surgery Procedures / Q000009:adverse effects*; D012060:Rejuvenation; D012867:Skin / Q000528:radiation effects; D015595:Skin Aging / Q000528:radiation effects*