title: Clinical and histologic evaluation of psoriatic plaques treated with a flashlamp pulsed dye laser.
abstract: BACKGROUND
  Psoriatic plaques can be cleared by destruction of the dermal papillae. Dilated vessels, the major component of psoriatic dermal papillae, can be selectively destroyed with yellow light lasers. Previous investigators have demonstrated partial clearing of psoriatic plaques after treatment with a pulsed dye laser (PDL) (585 nm).
  
  
  OBJECTIVE
  This study was designed to examine the clinical and histologic events of psoriasis treated with the PDL.
  
  
  METHODS
  Psoriatic plaques were treated with a short (450 microseconds) and long (1500 microseconds) pulse-width PDL. Photographs of the plaques were used for clinical assessment. Biopsy specimens were examined microscopically.
  
  
  RESULTS
  Significant clinical improvement was seen, and no significant difference between the long and short pulse-width lasers was found. Patients responding to treatment with the PDL remained in remission for up to 13 months. Histologic normalization occurred after treatment. Two pretreatment vascular patterns were seen: vertically oriented vessels with few horizontal vessels and numerous tortuous vessels. Tortuous vessels were associated with poor clinical results.
  
  
  CONCLUSIONS
  The PDL can induce prolonged remission in chronic plaque psoriasis. The vascular pattern may help to distinguish those patients likely to respond to this treatment.
authors.affiliation: Department of Dermatology, University of Minnesota Medical School, Minneapolis 55455, USA.
authors.forename: B D
authors.initials: BD
authors.lastname: Zelickson
authors.forename: D A
authors.initials: DA
authors.lastname: Mehregan
authors.forename: G
authors.initials: G
authors.lastname: Wendelschfer-Crabb
authors.forename: D
authors.initials: D
authors.lastname: Ruppman
authors.forename: A
authors.initials: A
authors.lastname: Cook
authors.forename: P
authors.initials: P
authors.lastname: O'Connell
authors.forename: W R
authors.initials: WR
authors.lastname: Kennedy
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D001808:Blood Vessels / Q000473:pathology; D004108:Dilatation, Pathologic / Q000473:pathology / Q000628:therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053685:Laser Therapy; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D010789:Phototherapy / Q000379:methods*; D011565:Psoriasis / Q000473:pathology / Q000628:therapy*; D012074:Remission Induction; D012867:Skin / Q000098:blood supply / Q000473:pathology; D016896:Treatment Outcome