NELL BOYCE: This is Nell Boyce.
Some researchers are abandoning poison shampoos and taking a different approach: searching for a physical, mechanical way of killing lice. Sort of like a stake through the heart for these little vampires. One idea is drying them out, sucking out their moisture until they're little harmless husks.
Dale Clayton at the University of Utah has been working on this idea. His first experiment was kind of disgusting.
Mr. DALE CLAYTON (University of Utah): I actually took bird lice and sprinkled them in my hair. Live ones.
BOYCE: Clayton knew bird lice don't infect humans.
Mr. CLAYTON: And I put on a bonnet-style hair dryer and watched TV for about 20 minutes. And then combed the lice out to see if they were still alive.
BOYCE: And they were. Then he tried a handheld hair dryer. It didn't work either. But Clayton kept at it and eventually developed a hot air blower the size of a small vacuum cleaner. It has a hose and a nozzle with teeth like a rake. It really blows.
Mr. CLAYTON: Our machine runs at twice the volume of a blow dryer. And importantly, you also need to lift the hair, exposing the roots where the eggs and the lice tend to hang out.
BOYCE: Clayton published a study in the journal, Pediatrics. It showed a kid with two feet of hair could be treated by this louse-buster in under an hour. Although raking a comb through the hair, while hot air is blowing in the opposite direction, makes for a bad hair day.
Mr. CLAYTON: It does get tangled to some extent, and this is the price one pays for this method.
BOYCE: Actually, the real price is likely to be hundreds of dollars. Clayton's team is seeking approval from the Food and Drug Administration and plans to sell this gadget to schools and clinics.
Another invention, already on the market, is a comb with a bug zapper built into the teeth. The whining sound stops briefly when the teeth electrocute a louse. That's satisfying, but the comb can go silent when it hits other stuff like dirt or moisture.
Mr. IAN BURGESS (Head of Medical Entomology Center in England): You often get a lot of false-positive noises, and which makes some people feel happy because they're not aware what's going on.
BOYCE: Ian Burgess heads a research organization in England called the Medical Entomology Center. He studied electric combs but is more impressed with another way to kill lice - a slippery lotion made with silicone that coats the bugs.
Mr. BURGESS: And effectively, it acts like shrink-wrapping.
BOYCE: This shrink-wrapping seems to have set their ability to evaporate water from their bodies. Their guts rupture and they die. This product is on the market in Europe and may come here next year. Now you might thing that shrink-wrapping would kill a louse by suffocating it. But Burgess says the bugs have tricks that make them extremely hard to asphyxiate.
Mr. BURGESS: If you immerse a louse in water it shuts down its breathing system.
BOYCE: And once a louse closes its breathing holes, it can sit pretty for hours and hours.
Mr. BURGESS: So drowning or asphyxiation is not really a viable option.
BOYCE: But people keep trying. Mike Precopio of Summers Laboratories has developed a new formulation. He says it contains an alcohol.
Mr. MIKE PRECOPIO (Summers Laboratories): When you use this benzyl alcohol, it isn't a pesticide but it sort of anesthetizes the lice.
BOYCE: He says the stunned lice don't shut their breathing holes down.
Mr. PRECOPIO: And so, while their breathing apparatus is open, it really doesn't take that much to coat the lice and cause asphyxiation.
BOYCE: His company calls this product the Lice Choker. They're doing a clinical trial now and they hope to apply for FDA approval next year.
Nell Boyce, NPR News.
MONTAGNE: There are a lot of myths about head lice. Find out about the truth at NPR.org/yourhealth.
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