Single application of 4% dimeticone liquid gel versus two applications of 1% permethrin creme rinse for treatment of head louse infestation: a randomised controlled trial

BMC Dermatol. 2013 Apr 1;13:5. doi: 10.1186/1471-5945-13-5.


Background: A previous study indicated that a single application of 4% dimeticone liquid gel was effective in treating head louse infestation. This study was designed to confirm this in comparison with two applications of 1% permethrin.

Methods: We have performed a single centre parallel group, randomised, controlled, open label, community based trial, with domiciliary visits, in Cambridgeshire, UK. Treatments were allocated through sealed instructions derived from a computer generated list. We enrolled 90 children and adults with confirmed head louse infestation analysed by intention to treat (80 per-protocol after 4 drop outs and 6 non-compliant). The comparison was between 4% dimeticone liquid gel applied once for 15 minutes and 1% permethrin creme rinse applied for 10 minutes, repeated after 7 days as per manufacturer's directions. Evaluated by elimination of louse infestation after completion of treatment application regimen.

Results: Intention to treat comparison of a single dimeticone liquid gel treatment with two of permethrin gave success for 30/43 (69.8%) of the dimeticone liquid gel group and 7/47 (14.9%) of the permethrin creme rinse group (OR 13.19, 95% CI 4.69 to 37.07) (p < 0.001). Per protocol results were similar with 27/35 (77.1%) success for dimeticone versus 7/45 (15.6%) for permethrin. Analyses by household gave essentially similar outcomes.

Conclusions: The study showed one 15 minute application of 4% dimeticone liquid gel was superior to two applications of 1% permethrin creme rinse (p < 0.001). The low efficacy of permethrin suggests it should be withdrawn.

Trial registration: Current Controlled Trials ISRCTN88144046.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Analysis of Variance
  • Animals
  • Child
  • Child, Preschool
  • Dimethylpolysiloxanes / administration & dosage*
  • Drug Administration Schedule
  • Female
  • Gels / administration & dosage
  • Humans
  • Insecticides / administration & dosage*
  • Lice Infestations / drug therapy*
  • Male
  • Middle Aged
  • Pediculus*
  • Permethrin / administration & dosage*
  • Treatment Outcome
  • Young Adult


  • Dimethylpolysiloxanes
  • Gels
  • Insecticides
  • Permethrin
  • dimethicone

Associated data

  • ISRCTN/ISRCTN88144046