Lice are Lousy but not Unhealthy

Updated June 2010

Head lice are not a popular topic of conversation or research, but maybe they should be — 6 to 12 million children (mostly ages 3-12) have them every year. A 2002 report from the American Academy of Pediatrics sets the record straight and makes clear recommendations that may surprise many parents, teachers, school administrators, and youth workers at residential treatment centers and other centers where lice are a potential problem.

The report starts with the statement that “Head lice are not a health hazard or a sign of uncleanliness and are not responsible for the spread of any disease.” It explains that lice affect all socio-economic groups, but are less common among blacks, apparently because their oval-shaped hair shafts are harder for a louse (that’s the singular of lice!) to grasp.

While it is nearly impossible to totally prevent head lice infestations, it helps to teach children not to share combs, brushes and hats. And although schools and day care centers usually require children with lice to go home, the 2002 report from the American Academy of Pediatricians points out that a child with live lice has probably had the lice for a month or more by the time they are discovered, and the child poses little risk to others, and should therefore remain in school. However, they ¬†should be discouraged from having “close head contact” with others. The report recommends that the information about a child’s lice be confidential rather than public, with a call to the parent or guardian stating that prompt treatment is in the child’s best interest. Exceptions might be necessary if a child has hundreds of live lice.

School policies

The American Academy of Pediatrics (AAP) and the National Association of School Nurses discourage the “no nits” policy that many schools have established. Nits are the tiny lice eggs, which can be easier to spot than live lice, since lice crawl up to 30 cm (nearly 12 inches) per minute. “No nits” policies are especially problematic because empty lice egg cases, dandruff, or even dirt can be mistaken for nits.

A study of 1,729 children in two elementary schools looked at how many children with nits will go on to have head lice. The study found that about 5% of the children had lice and that only a relatively small proportion of kids with nits become infected with lice. According to school policy, all children found to have lice had to be picked up from school by their parents and could not return to school without proof of treatment. However, of 50 children with nits but no lice, only nine (18 percent) became infected with lice during the following two weeks. The total number of nits that a child had in his or her hair did not predict whether a child would become infected. Even more surprising, whether or not the children received treatment for lice did not affect whether or not the children with nits ended up with lice.

The authors of the study conclude that many children who are not infectious and will not themselves get lice are being removed from schools that have a “no nits” policy. In addition, requiring treatment for nits may be inappropriate, since there was no evidence that it decreased the likelihood of subsequent infestation.

Treatments

Treatments include a variety of toxic and not-so-toxic shampoos and creams. The AAP report describes Nix as a cream rinse that is the “recommended treatment of choice” because it is less toxic to humans than other products and does not cause allergic reactions to children with plant allergies. It describes Lindane as a prescription product that must be used extremely carefully, can cause severe seizures in children, and is not very effective. Malathion is also a prescription lotion; although it is also a neurotoxin, its greater danger is that it is highly flammable and very dangerous if ingested. Several lice shampoos are made from extracts from chrysanthemums — RID, A-200, R & C, Pronto, and Clear Lice System. These are neurotoxic to lice but not very dangerous to humans. However, some children and adults have allergic reactions, especially those who are sensitive to ragweed.

The report also lists several products that are sometimes used but not proven safe or effective for lice: creams such as Elimite and Eurax, pills such as Septra, Bactrim, and Stromectal, natural products such as HairClean 1-2-3, and “petrolatum shampoo.” Old-fashioned treatments such as gasoline, kerosene, and other flammable substances “should never be used” according to the report.

The report summary emphasizes that head lice screening programs are not cost-effective and often are not effective at all, and that healthy children with lice should not be excluded from school nor even allowed to miss school because of lice.

References
Head Lice. American Academy of Pediatrics Clinical Report.
Pediatrics, Vol 110 No 3, September 2002. Available online at http://www.aap.org/policy/0203.html

L. Keoki Williams, M.D., Amanda Reichert, M.A., William R. MacKenzie, M.D and colleagues. Lice, Nits, and School Policy. .Pediatrics, Vol 107, No 5 May 2001. Available online at http://pediatrics.aappublications.org/cgi/content/abstract/107/5/1011