title: The influence of psoriatic plaques pretreatment with crude coal tar vs. petrolatum on the efficacy of narrow-band ultraviolet B: a half-vs.-half intra-individual double-blinded comparative study.
abstract: OBJECTIVE
  The value of psoriatic plaques pretreatment with specific topical preparations in the setting of NB-ultraviolet-B (UVB) therapy is debatable. It may be clarified through a comparative assessment between crude coal tar and petrolatum as pretreatment candidates.
  
  
  METHODS
  A prospective study included 40 patients with plaque psoriasis undergoing NB-UVB therapy. We compared among three treatment regimens: NB-UVB alone (control group; n=20) as well as NB-UVB preceded by crude coal tar 3% on one side and petrolatum on the other side (cases group I and II; n=20). Tar and petrolatum were topically applied thrice/day the day before NB-UVB exposure. Applications were removed using olive oil directly before NB-UVB exposure. Regimens' frequency was thrice/week and the clinical outcome was assessed, through both psoriasis area and severity index (PASI) and physician global assessment (PGA) scores, at baseline and 3 months later.
  
  
  RESULTS
  There were significant (P<0.01) decreases in both PASI and PGA scores in all the groups. In comparison with the controls, cases revealed significantly (P<0.05) higher improvement percentages in both PASI and PGA scores for both tar and petrolatum. This influence, through the PGA score, was significantly (P<0.05) in favor of petrolatum.
  
  
  CONCLUSIONS
  The pretreatment of psoriatic plaques with either petrolatum or crude coal tar may enhance the therapeutic outcome of NB-UVB, which appeared to favor petrolatum.
authors.affiliation: Department of Dermatology, Venereology and Andrology, Ain Shams University, Cairo, Egypt.
authors.forename: Marwa A
authors.initials: MA
authors.lastname: Abdallah
authors.forename: Ekramy Ahmed
authors.initials: EA
authors.lastname: El-Khateeb
authors.forename: Shereen H
authors.initials: SH
authors.lastname: Abdel-Rahman
mesh_terms: D000287:Administration, Topical; D000328:Adult; D003033:Coal Tar / Q000008:administration & dosage*; D004311:Double-Blind Method; D004643:Emollients / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007641:Keratolytic Agents / Q000008:administration & dosage*; D008297:Male; D010577:Petrolatum / Q000008:administration & dosage*; D011446:Prospective Studies; D011565:Psoriasis / Q000532:radiotherapy*; D014466:Ultraviolet Rays; D014467:Ultraviolet Therapy / Q000379:methods*
chemical_list: D004643:Emollients; D007641:Keratolytic Agents; D003033:Coal Tar; D010577:Petrolatum