Tocopheryl acetate 20% spray for elimination of head louse infestation: a randomised controlled trial comparing with 1% permethrin creme rinse

BACKGROUND: Tocopheryl acetate is viscous oily fluid used in a range of preparations for skin and scalp care in Italy. Observational and in vitro data have suggested a high level of efficacy against head louse infestation. The purpose of this investigation was to confirm the activity of tocopheryl acetate in a clinical setting in comparison with a standard widely used preparation. METHODS: A spray formulation containing tocopheryl acetate 20% in cyclomethicone was compared with permethrin 1% creme rinse for treatment of head louse infestation in a randomised, assessor blind, trial. Forty-five people were treated on two occasions 7 days apart. The spray was applied to dry hair for 20 minutes then washed. Participants treated with permethrin washed their hair and towel dried it before treatment for 10 minutes. Assessments were made by dry detection combing 1, 6, 9, and 14 days after first treatment. RESULTS: The tocopheryl acetate 20% spray was significantly (p = 0.033) more effective than permethrin 1%, using intention to treat worst case analysis, in which there were 13/23 (56.5%) successful treatments for tocopheryl acetate compared with 5/22 (22.7%) for permethrin. After unprecedented issues of re-infestation within households had been taken into account the underlying cure rate was 17/23 (73.9%) for tocopheryl acetate compared with 5/22 (22.7%), Odds Ratio 9.63 (95% CI, 2.46 to 37.68) (p < 0.001). CONCLUSIONS: The tocopheryl acetate spray was significantly more effective than the permethrin product, was cosmetically acceptable, and not affected by current problems with resistance. TRIAL REGISTRATION: Current Controlled Trials ISRCTN45553737.