Blow Away Head Lice

By Lucy Williams, Ivanhoe Health Correspondent

ORLANDO, Fla. (Ivanhoe Newswire) -- A blast of hot air could be the key to killing head lice. When researchers at the University of Utah in Salt Lake City had trouble keeping lice hydrated and alive in the lab, they realized the dry air could effectively kill the insects and halt infestation.

Small insects are susceptible to desiccation, or drying, because they have a high surface area-to-volume ratio. When lice become dehydrated, they die. Researchers used this idea to develop the LouseBuster, a hairdryer-like device that kills lice using hot air.

"It's easy for insects to evolve resistance to the many chemicals in head lice shampoos," study leader and machine inventor Dale Clayton, Ph.D., of the University of Utah in Salt Lake City, told Ivanhoe. "It would be a lot more difficult for them to evolve a new water physiology, which is what they would need to deal with this."

In the study, the LouseBuster killed 98 percent of eggs and 80 percent of hatched lice in infested individuals. Researchers think this kill rate is high enough to prevent remaining lice from breeding. The heat may also leave remaining lice sterile or too stressed to reproduce.

Between 6 million and 12 million cases of head lice occur in the United States each year, and the number is growing as the insects become resistant to some chemical treatments. Other treatments, like the louse comb and home remedies, can be time-consuming or even harmful to patients.

The LouseBuster treatment, in contrast, takes just 30 to 35 minutes and causes very little discomfort. The LouseBuster is a dryer attached to a plastic hand piece with 10 teeth that comb through the hair while hot air blows in the opposite direction. The machine blows about twice as fast as a hairdryer. Dr. Clayton said, "It's like sticking your head out a car window that's going 150 mph, so it dries out pretty fast."

Don't try to kill head lice at home with hot air just yet. The LouseBuster is not available for consumers, and although the device is similar to a hairdryer, it could be dangerous to use a hairdryer to kill head lice.

"We don't want people trying to treat head lice with blow dryers because they're too hot, and it's easy to burn a child with that much heat," said Dr. Clayton. "And it doesn't work. You have to lift the hair in a particular way to kill all of the lice."

Dr. Clayton said he hopes the device will be on the market in one year or two years.

This article was reported by Ivanhoe.com, who offers Medical Alerts by e-mail every day of the week. To subscribe, go to: http://www.ivanhoe.com/newsalert/.

SOURCE: Ivanhoe interview with Dale Clayton, Ph.D., University of Utah in Salt Lake City; PEDIATRICS, 2006;118:1962-1970