Study Finds Key to Unlock Lices Grip on Hair

As the new school year approaches, parents of elementary school children may want to consider adding a lice comb to their school supplies shopping list. This annoying, but increasingly common problem will affect more than 6 million American elementary school children this year.

Contrary to popular myths about hair texture, hygiene and social background, anyone can become infested with lice. Young children are particularly susceptible because they tend to share things like hats and hairbrushes, which can harbor lice.

Lice are equal opportunity, said Craig N. Burkhart, MD, lead author of the study that appeared in the July 2005 issue of the Journal of the American Academy of Dermatology, and on staff at the University of North Carolina at Chapel Hill Department of Dermatology. They affect people of all ages, sexes, races and socioeconomic levels.

Burkhart reviewed research on current lice treatments and discussed possible new ones based on a better understanding of the glue that female lice use to attach their eggs to the hair shaft.

The available lice treatments do not reliably kill the louse egg and the increasing prevalence of lice in certain locations throughout the world suggests that lice have built up a resistance to the chemicals that are used to kill them, Burkhart said.

Human head lice, like many other insects, apply a protective coating, or glue, over their newly laid eggs. Called the nit sheath, this coating is made up of a protein that is remarkably similar to that of human hair and serves to protect the developing larva. Because of this, anything that would be effective at dissolving the nit sheath also would dissolve the hair shaft.

"A treatment that could prevent the glue from solidifying on the nit sheath would prevent the egg from adhering to the hair. Such treatment would be beneficial to both people with lice infestation and those who are trying to avoid acquiring one, Burkhart said. A liquid parafin preparation, similar to that used to prevent bird eggs from hatching, also could possibly suffocate the larva by severely decreasing the flow of oxygen to it.

Burkhart thinks that other potential for new treatments will be breaking the bonds that attach the egg to the hair shaft and thus allow for easier nit removal, rather than insecticidal treatments that kill the lice and their eggs. Nevertheless, the insecticide, ivermectin, in a topical form in an oil base also shows great promise.

If you think that your child has developed a lice problem, you should seek treatment from a dermatologist so that he or she does not infect others, Burkhart said.

Source: American Academy of Dermatology