The appearance of head lice strikes fear into many parents' hearts because eradicating bugs and nits (egg casings) from the hair—as many schools require before they'll let children back into class—traditionally entails the use of chemical shampoos and a frenzied bout of housecleaning. But even as lice have developed resistance to many existing ingredients, research has identified two safer approaches that may be at least as effective. Meanwhile, other research suggests that lice don't survive long off the scalp, making extensive vacuuming and laundering of clothing, sheets, pillows, and blankets unnecessary.

The simplest approach, described in an August 2005 article in the British Medical Journal, involves thoroughly combing your child's wet hair with a special fine-toothed nit comb. That technique eradicated lice in about 60 percent of cases, vs. the 15 percent cure rate of people in the study who used two standard medications, permethrin (Nix) and malathion (Ovide).

The other technique, developed by a California doctor and reported in the September 2004 issue of Pediatrics, was even more effective, eliminating lice in more than 90 percent of patients. The author says the technique—which involves coating the hair with Cetaphil, a widely available over-the-counter face cleanser, and then blow-drying it—kills lice by forming a shrink-wrap-like coating and suffocating them. It worked equally well even when parents didn't launder their child's bedding or remove nits from his or her hair.

What you can do. For wet combing, first coat the hair and scalp with any regular hair conditioner, then comb it out with a nit comb, available in most drug stores; repeat four times, with a three-day break in between each session. For the suffocation technique, soak the scalp and dry hair with Cetaphil (or its store-brand equivalent), blow the hair dry, and leave untouched for eight hours. Then wash and comb the hair with a regular fine-toothed comb. (For details, see www.nuvoforheadlice.com/method_explained.htm.) If those approaches don't work, try 1 percent permethrin or pyrethrin (Rid), another over-the-counter insecticide shampoo. Reserve the prescription drug malathion (Ovide) for extremely stubborn and severe cases. You should leave the product in your child's hair for only about 15 minutes (not eight hours, as the label instructs), which studies have shown is long enough to kill the lice and nits.