Advertisement
YOU ARE HERE: LAT HomeCollectionsFixme
(Page 2 of 2)

MEDICINE | IN THE LAB

Victory in louse wars?

Head lice -- yuck -- have developed a creeping resistance to common insecticides. Maybe it's time for a new tack -- like blasting them with hot air.

November 13, 2006|Regina Nuzzo | Special to The Times

Using conditioner with combing is highly touted by public health groups in Britain, Burgess says -- but the technique has yet to receive widespread endorsement in the U.S.

Quick drying, rather than slow leaking, is the idea behind a new desiccation device that promises to treat an infestation in as little as 30 minutes.

The LouseBuster, a portable hot-air machine with a flexible hose, can expel twice as much air as a hair dryer. Its blast of 140-degree air can suck the moisture out of whatever happens to be in its path -- be they adult lice clinging to hair strands or eggs cemented to the strands' base.

"It would be like sticking your head out of a car window at 150 mph," says Dale Clayton, a professor of biology at the University of Utah and co-inventor of the LouseBuster. "That would dry out your eyeballs right away."

In a study published in Pediatrics this month, Clayton and his colleagues tested the new device and other hot-air methods on 169 lice-infested children in Utah.

By slowly raking a nozzle expelling hot air along the scalp, the LouseBuster killed 80% of adult lice and 98% of eggs, even when operating at a slightly cooler temperature than a normal hair dryer.

A week after being treated with the new device, all of the infestations had disappeared. There were no reported aftereffects, not even dry scalps, Clayton says.

The LouseBuster is being developed by a University of Utah spinoff company called Larada Sciences, for which Clayton is chief scientific officer. The patent-pending technology is going through the Food and Drug Administration review process, Clayton says, and he hopes it will be available within a couple of years.

Home hair dryers are no substitute for the new device, he says. For one thing, they don't perform as well as the LouseBuster, which has a wide-tooth comb at the end of the hose that helps direct the air to the scalp. More important, it's easy for overzealous parents to burn delicate scalps.

The price is still uncertain, but Clayton expects the LouseBuster to be available for schools and clinics for a few hundred dollars.

Not all nifty ideas end up making a difference in the head lice war, however. A few years ago, Spiesel invented a shampoo that causes louse eggs to glow brightly under the right conditions, making them easier for parents to pick out. Sadly, the formulation is still sitting in the lab without a developer. Spiesel is philosophical about the demise of the product, which he once thought of calling HeadLights.

"It's a shame, but it's not like it was an antibiotic that would save lives," he says. "It's just head lice."

*

(BEGIN TEXT OF INFOBOX)

Settling into a new home

Head louse research is a lot more fun these days than it was 10 years ago. Until very recently, scientists studying head lice were forced to walk around with tubes of head lice strapped to their legs. The researchers' own blood fed the hungry critters every few hours.

Scientists can now rear thriving colonies of hundreds of human head lice on simulated scalps in the lab. Instead of fresh scientist's blood, the lice enjoy a meal of reconstituted blood donated from the Red Cross. The lice live on artificial membranes of paraffin and scurry around artificial forests of hair laying clutches of eggs every few days.

Unfortunately, some newly hatched young never figure out the system, says John Clark, professor of environmental toxicology at the University of Massachusetts at Amherst.

And for adults brought in from the wild, a simulated scalp doesn't seem to satisfy -- probably because such lice have had a taste of real blood the way nature intended. "Once that happens, everything else is not fine," Clark says.

Scientists use the artificial scalps to conduct experiments on lice that can't safely be done on lice residing on people. Clark, for example, is looking for compounds that entice lice to crawl to a designated spot on the scalp for easy pickup and disposal.

Advertisement
Los Angeles Times Articles
|
|
|