It was an e-mail message signed "Helpless and Hopeless in Wheeling," from a mother whose daughter was diagnosed with head lice six months ago. "Please, if there is ANY home remedy, anything at all that you think I could do to get rid of these things, I'm begging you, please let me know," the woman wrote. "I'm afraid to go to friends' and families' houses, in fear that we will give it to them as well."

Inundated by half-a-dozen of this kind of e-mail message almost every day, Richard Pollack, an instructor in the Department of Immunology and Infectious Diseases, decided about a year ago to set up an informational Web site rather than try to respond to every message individually. So last November the School's head lice information page came into being (www.hsph.harvard.edu/headlice.html).

In addition to answering some frequently asked questions about lice, Pollack decided to include a solicitation for specimens from suspected cases. People are asked to download a simple one-page form, use clear tape to attach a sample, and send both to Pollack's lab. "It is kind of an interesting example of collecting data and specimens at virtually no cost--unless you count my time," he says.

Pollack has received well over 100 samples from all over the country. He's seen a lot of dandruff, tiny pieces of scalp, globs of hair spray, and other common and completely harmless insects such as thrips and springtails. There have also been some book lice, which dine on paper and other organic matter and are a major worry for librarians but are completely harmless to humans. And among the vast majority of specimens that actually did contain eggs, the eggs were hatched or dead, indicating an old infestation, but not something that warranted treatment.

But so far what Pollack hasn't seen a lot of is active Pediculus capitis, or head lice. He says: "The take-home message here is that if you talk to the people in the general public or the medical community, we are experiencing an epidemic of pediculosis [lice infestation]. But what we are finding is that there is an epidemic of hysteria and not true pediculosis."

Pollack says there are a lot of reasons for overdiagnosis, which, of course, perpetuates the hysteria. Some physicians diagnose over the phone. School nurses, relying on their years of experience, can be too sure of their ability to identify lice with the naked eye or to distinguish between an active and inactive infestation. Worried parents jump to conclusions. And in Pollack's opinion, school programs that enlist parent volunteers to come in one or two days a year to inspect children's hair and scalp are probably counter-productive, as they lead to more misdiagnoses.

While the Internet has given Pollack an interesting window on the world of pediculosis, he notes that the Internet also manages to spread a lot of bad information. Web sites on head lice have proliferated, and, says Pollack, many, if not most, of them are shoddy, perpetuating false wisdoms (such as if you blow on it and it comes off, it is probably dandruff, but if it sticks, it is probably lice eggs). "There is just too much misinformation out there. The general public seems to think that if it is in print, anywhere, then it is right," laments Pollack.

"There is just too much misinformation out there," says Richard Pollack.


Because they don't transmit pathogens, head lice in the United States are more of a nuisance than a bona fide health threat. But this widespread overdiagnosis of head lice infestation--by some estimates, 12 million supposed cases identified each year- does have some serious consequences, not the least of which are distraught parents and children. According to Pollack's Web site, "The greatest harm associated with head lice results from well-intentioned but misguided use of caustic or toxic substances to eliminate the lice."

And while the insecticide most commonly used, permethrin, is generally safe, Pollack adds that no one wants to be needlessly exposing children to insecticides. Moreover, the insecticide-based treatment might not even be effective: Pollack and his colleagues are studying whether lice have become resistant to permethrin. A head lice diagnosis, whether accurate or not, can also force children to miss days, if not months, of school and parents to lose large chunks of work time because many school districts have a "no nits" policy that forbids attendance.

To get a better handle on the true prevalence of head lice, Pollack and his colleagues plan to study in cooperation with daycare centers and elementary schools, using specially trained staff to accurately diagnose and document cases. The information derived from responses to his Web site will also provide the basis for a research paper.