Authors
  Zelickson BD.  Mehregan DA.  Wendelschfer-Crabb G.  Ruppman D.  Cook A. 
  O'Connell P.  Kennedy WR.
Title
  Clinical and histologic evaluation of psoriatic plaques treated with a
  flashlamp pulsed dye laser [see comments].
Comments
  Comment in: J Am Acad Dermatol 1997 Aug;37(2 Pt 1):288-9
Source
  Journal of the American Academy of Dermatology.  35(1):64-8, 1996 Jul.
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. CONCLUSION: 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.