title: The effect of different pulse durations in the treatment of nail psoriasis with 595-nm pulsed dye laser: a randomized, double-blind, intrapatient left-to-right study.
abstract: BACKGROUND
  Several studies have proven the efficacy of pulsed dye laser (PDL) in the treatment of plaque type psoriasis. However, only two published studies indicate the effectiveness of PDL on nail psoriasis.
  
  
  OBJECTIVE
  We sought to study the effect of different pulse durations in the treatment of nail psoriasis with the 595-nm PDL to determine the optimal pulse duration.
  
  
  METHODS
  Twenty patients with bilateral fingernail psoriasis were recruited and completed a 6-month trial. PDL was applied on the proximal and lateral nailfolds based on random assignment. Forty nails were treated with 6-millisecond pulse duration and 9 J/cm(2) whereas 39 nails were treated with 0.45-millisecond pulse duration and 6 J/cm(2). Patients were blinded to pulse durations. One blinded dermatologist used the Nail Psoriasis Severity Index (NAPSI) to assess the clinical outcome from pretreatment and posttreatment photographs. Patients were monitored for adverse events. Pain was evaluated after the procedure using a visual analog scale assessed by the patient.
  
  
  RESULTS
  After 6 months of first treatment, there was a significant reduction in overall NAPSI, nail matrix NAPSI, and nail bed NAPSI scores from baseline in both groups; however, no significant difference was found between the two pulse duration groups. Side effects were mild including transient petechiae and hyperpigmentation.
  
  
  CONCLUSIONS
  There was no placebo group.
  
  
  CONCLUSIONS
  PDL was found to be an effective and well-tolerated option in the treatment of nail psoriasis. No significant difference in terms of efficacy was found between the longer and shorter pulse duration treatment groups.
authors.affiliation: Division of Dermatology, Department of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand. chanitwan@yahoo.com
authors.forename: Chanitwan
authors.initials: C
authors.lastname: Treewittayapoom
authors.forename: Piyavadee
authors.initials: P
authors.lastname: Singvahanont
authors.forename: Kumutnart
authors.initials: K
authors.lastname: Chanprapaph
authors.forename: Eckart
authors.initials: E
authors.lastname: Haneke
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007297:Inpatients / Q000706:statistics & numerical data; D054025:Lasers, Dye / Q000627:therapeutic use*; D028022:Low-Level Light Therapy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009260:Nail Diseases / Q000175:diagnosis / Q000532:radiotherapy*; D011565:Psoriasis / Q000175:diagnosis / Q000532:radiotherapy*; D012016:Reference Values; D012720:Severity of Illness Index; D013785:Thailand; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult