title: Cryotherapy with liquid nitrogen versus topical salicylic acid application for cutaneous warts in primary care: randomized controlled trial.
abstract: BACKGROUND
  Cryotherapy is widely used for the treatment of cutaneous warts in primary care. However, evidence favours salicylic acid application. We compared the effectiveness of these treatments as well as a wait-and-see approach.
  
  
  METHODS
  Consecutive patients with new cutaneous warts were recruited in 30 primary care practices in the Netherlands between May 1, 2006, and Jan. 26, 2007. We randomly allocated eligible patients to one of three groups: cryotherapy with liquid nitrogen every two weeks, self-application of salicylic acid daily or a wait-and-see approach. The primary outcome was the proportion of participants whose warts were all cured at 13 weeks. Analysis was on an intention-to-treat basis. Secondary outcomes included treatment adherence, side effects and treatment satisfaction. Research nurses assessed outcomes during home visits at 4, 13 and 26 weeks.
  
  
  RESULTS
  Of the 250 participants (age 4 to 79 years), 240 were included in the analysis at 13 weeks (loss to follow-up 4%). Cure rates were 39% (95% confidence interval [CI] 29%-51%) in the cryotherapy group, 24% (95% CI 16%-35%) in the salicylic acid group and 16% (95% CI 9.5%-25%) in the wait-and-see group. Differences in effectiveness were most pronounced among participants with common warts (n = 116): cure rates were 49% (95% CI 34%-64%) in the cryotherapy group, 15% (95% CI 7%-30%) in the salicylic acid group and 8% (95% CI 3%-21%) in the wait-and-see group. Cure rates among the participants with plantar warts (n = 124) did not differ significantly between treatment groups.
  
  
  CONCLUSIONS
  For common warts, cryotherapy was the most effective therapy in primary care. For plantar warts, we found no clinically relevant difference in effectiveness between cryotherapy, topical application of salicylic acid or a wait-and-see approach after 13 weeks. (ClinicalTrial.gov registration no. ISRCTN42730629).
authors.affiliation: Department of Public Health and Primary Care, Leiden University Medical Center, Leiden, the Netherlands. s.c.bruggink@lumc.nl
authors.forename: Sjoerd C
authors.initials: SC
authors.lastname: Bruggink
authors.forename: Jacobijn
authors.initials: J
authors.lastname: Gussekloo
authors.forename: Marjolein Y
authors.initials: MY
authors.lastname: Berger
authors.forename: Krista
authors.initials: K
authors.lastname: Zaaijer
authors.forename: Willem J J
authors.initials: WJ
authors.lastname: Assendelft
authors.forename: Margot W M
authors.initials: MW
authors.lastname: de Waal
authors.forename: Jan Nico Bouwes
authors.initials: JN
authors.lastname: Bavinck
authors.forename: Bart W
authors.initials: BW
authors.lastname: Koes
authors.forename: Just A H
authors.initials: JA
authors.lastname: Eekhof
mesh_terms: D000287:Administration, Topical; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D017679:Cryotherapy / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006801:Humans; D007641:Keratolytic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D009584:Nitrogen / Q000008:administration & dosage; D020156:Salicylic Acid / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome; D014860:Warts / Q000188:drug therapy / Q000628:therapy*
chemical_list: D007641:Keratolytic Agents; D009584:Nitrogen; D020156:Salicylic Acid