title: A comparison of three times vs. five times weekly narrowband ultraviolet B phototherapy for the treatment of chronic plaque psoriasis.
abstract: BACKGROUND
  Narrowband ultraviolet B (NB-UVB) phototherapy is an effective treatment for psoriasis.
  
  
  OBJECTIVE
  To compare the effects of three and five times weekly NB-UVB phototherapy in the treatment of chronic plaque psoriasis.
  
  
  METHODS
  Sixty-five patients with chronic plaque psoriasis were allocated to receive three or five times weekly NB-UVB, starting at low dose.
  
  
  RESULTS
  Among the patients who completed the study, clearance was achieved in 18 out of 23 patients (78%) in the three times weekly group and in 15 out of 22 patients (68%) in the five times weekly group. The difference was not statistically significant (P=0.44). No statistically significant differences were found between the two groups in the number of treatments (P=0.95), cumulative UVB dose (P=0.51), and rate of side-effects. Length of the treatment period was significantly shorter in the five times weekly group (P<0.001). At the end of treatment, the mean psoriasis area and severity index score was lower in the three times weekly group (P=0.02).
  
  
  CONCLUSIONS
  We recommend three times weekly NB-UVB for chronic plaque psoriasis; however, the more rapid clearance of psoriasis with five times weekly phototherapy may justify using this method in some patients.
authors.affiliation: Department of Dermatology, Razi Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Hallaji
authors.forename: Masoumeh
authors.initials: M
authors.lastname: Barzegari
authors.forename: Kamran
authors.initials: K
authors.lastname: Balighi
authors.forename: Pouria
authors.initials: P
authors.lastname: Mansoori
authors.forename: Arash
authors.initials: A
authors.lastname: Taheri
authors.forename: Parisa
authors.initials: P
authors.lastname: Mansoori
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002908:Chronic Disease; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011565:Psoriasis / Q000532:radiotherapy*; D013997:Time Factors; D014467:Ultraviolet Therapy