The efficacy of permethrin lotion in pediculosis capitis.

A clinical trial of the pyrethroid permethrin in 1% lotion was performed on 20 children. Ten were treated for 10 minutes and 10 for 2 hours. All lice washed off the heads of children treated for 2 hours were dead immediately after treatment. Twenty-four percent of the lice removed from one child treated for 10 minutes were still alive 2 hours later. The ovicidal effect was similar in both groups, with egg mortality 88% and 90% following 10-minute and 2-hour treatment, respectively. The mortality of untreated control eggs was 14% and 11%, respectively.