Lice Infestation Health Article

Allopathic treatment

All types of lice are treated allopathically with insecticidal lotions, shampoos, or cream rinses. However, experts disagree about the effectiveness and/or safety of pediculicides. Pediculicides do not kill nits, so nit removal and a second application in seven to 10 days may be necessary. Pediculicides can be poisonous if used improperly or too frequently and overuse can lead to the proliferation of chemically resistant lice. The residue may remain on the hair for several weeks and can cause skin or eye irritations.

Pediculicides should not be used:

• Near broken skin, eyes, or mucous membranes
• In the bathtub or shower
• By pregnant or nursing women or children under two
• By those with allergies, asthma, epilepsy, or some other medical conditions

Pyrethroids

All U.S. Food and Drug Administration (FDA)-approved non-prescription pediculicides contain relatively safe and effective pyrethroids. Insecticidal pyrethrins (0.33%) (RID, A-200) are extracts from chrysanthemum flowers. Permethrin (1%)(Nix) is a more stable synthetic pyrethrin. Pyrethroid pediculicides usually also contain 4% piperonyl butoxide.

To treat with pyrethroids:

• Apply for specified time, usually 10 minutes.
• Thoroughly rinse out.
• Do not wash hair for one or two days after treatment.
• Do not use cream rinse, hair spray, mousse, gels, mayonnaise, or vinegar before or within one week after treatment. These products may reduce pediculicide effectiveness

During the 1990s, as schools began requiring children to be lice and nit-free, the use of pyrethroids rose significantly and the FDA began receiving reports of ineffectiveness. The FDA ordered new labeling of pyrethroid pediculicides on the outside of the carton, in simpler language, and with more information, to take effect in 2005–2006. Permethrin sprays for treating mattresses, furniture, and other items are not recommended.

Other insecticides

Prescription insecticides are used when other lice treatments fail or cannot be used. These pesticides include:

• Malathion (0.5% in Ovide), a neurotoxic organophosphate, was withdrawn from the U.S. market due to an increase in malathion-resistant lice and re-introduced in 1999. It is foul-smelling and flammable. Sometimes infested clothing is treated with a 1% malathion powder
• Lindane (1% or higher) (Kwell), an organochloride neurotoxin, can induce seizures and death in susceptible people, even when used according to the directions. In 2003 the FDA required new labeling and a reduction in bottle size
• Ivermectin (Stromectol), an oral treatment for intestinal parasites, is effective against head lice but has not been approved for that use by the FDA

Infested eyelashes are treated with a thick coating of prescription petroleum ointment, applied twice daily for ten days.

Prognosis

Despite the presence of chemically resistant lice and the thoroughness required to prevent re-infestation, essentially all lice infestations can be eradicated eventually.

Prevention

Prevention of lice infestation depends on adequate personal hygiene and the following public health measures:

• Avoid sharing combs, brushes, hair accessories, hats, towels, or bedding
• Check hair and scalp weekly for lice and nits
• Limit sexual partners

Regular lice checks in schools and "no nit" re-entry policies have not been shown to be effective. The American Academy of Pediatrics, the Harvard School of Public Health, and the National Association of School Nurses recommend their elimination, although many healthcare professionals disagree.

Scientists have identified both the gene that enables head and body lice to digest blood and the gene that helps lice combat deadly infections, with the potential for new treatments and preventions for lice infestation.

BOOKS

Goldberg, Burton, et al. "Children's Health." Alternative Medicine: The Definitive Guide. 2nd ed. Berkeley, CA: Ten Speed Press, 2002.

Grossman, Leigh B. Infection Control in the Child Care Center and Preschool. Philadelphia: Lippincott Williams & Wilson, 2003.

PERIODICALS

Blenkinsopp, Alison. "Head Lice." Primary Health Care 13 (October 2003): 33–34.

Burgess, I. F. "Human Lice and Their Control." Annual Review of Entomology 49 (2004): 457.

Elston, D. M. "Drug-Resistant Lice." Archives of Dermatology. 139 (2003): 1061–1064.

Evans, Jeff "Pediatric Dermatology: Simple Methods Often Best: Lice, Mosquitoes, Warts." Family Practice News. 34 (January 15, 2004): 56.

Flinders, David C., and Peter De Schweinitz. "Pediculosis and Scabies." American Family Physician 69 (January 15, 2004): 341–352.

Heukelbach, Jorg, and Hermann Feldmeier. "Ectoparasites—The Underestimated Realm." Lancet 363 (March 13, 2004): 889–891.

Hunter, J. A., and S. C. Barker. "Susceptibility of Head Lice (Pediculus humanus capitis) to Pediculicides in Australia." Parasitology Research 90 (August 2003): 476–478.

Kittler, R., et al. "Molecular Evolution of Pediculus humanus and the Origin of Clothing." Current Biology 13 (August 19, 2003): 1414–1417.

"Recommendations Provided for Back-to-School Head Lice Problem." Health & Medicine Week October 6, 2003: 329.

Yoon, K. S., et al. "Permethrin-Resistant Human Head Lice, Pediculus capitis, and Their Treatment." Archives of Dermatology 139 (August 2003): 1061–1064.

Zepf, Bill. "Treatment of Head Lice: Therapeutic Options." American Family Physician 69 (February 1, 2004): 655.