Lice combs may outperform OTC chemicals

Head lice: Combing may outperform over-the-counter chemicals.

The question: Mere mention of head lice can make parents of young children squirm and then sigh, aware of the effort it will take to get rid of the varmints. With the tiny insects showing increasing resistance to commonly used insecticides, might special combs be an effective alternative?

This study randomly assigned 133 children with lice to have their heads treated with an over-the-counter insecticide (malathion or permethrin, mixed with water) or to have a fine-toothed comb methodically pulled through their wet hair after conditioner had been applied. Combing was done four times in about two weeks. A single dose of the chemical mixture was used, as recommended by the manufacturer. After treatment, head lice had disappeared from 57 percent of the combing group and 13 percent of those treated with an insecticide.

Who may be affected by these findings? Anyone who comes in close contact with someone who has head lice because the tiny, wingless, parasitic insects are highly contagious. Children are affected most often, through child care, school, sports and even slumber parties. Head lice do not indicate uncleanliness or poor hygiene.

Caveats: Use of a different type comb may yield different results; those used in the study were from a British “Bug Buster” kit available via the Internet. The authors noted that a double dose of insecticide most likely would kill lice that emerged from eggs not killed by the first dose, but that is considered an unlicensed use of the chemical in England, where the study was conducted. Although four times more effective than insecticides, the two-week combing process still did not eliminate lice from 43 percent of its users.

Find this study Aug. 5 online edition of BMJ; abstract available at www.bmj.com (click “Online first”).

Learn more about head lice at www.kidshealth.org and www.cdc.gov.