Head Lice

  • Medical Author:
    David Perlstein, MD, MBA, FAAP

    Dr. Perlstein received his Medical Degree from the University of Cincinnati and then completed his internship and residency in pediatrics at The New York Hospital, Cornell medical Center in New York City. After serving an additional year as Chief Pediatric Resident, he worked as a private practitioner and then was appointed Director of Ambulatory Pediatrics at St. Barnabas Hospital in the Bronx.

  • Medical Editor: William C. Shiel Jr., MD, FACP, FACR
    William C. Shiel Jr., MD, FACP, FACR

    William C. Shiel Jr., MD, FACP, FACR

    Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

Quick GuideHead Lice Treatment, Symptoms and Pictures

Head Lice Treatment, Symptoms and Pictures

What do head lice look like?

There are three forms of lice, namely the nit, the nymph, and the adult louse.

Nit: Nits are lice eggs. Nits are hard to see and are often confused with dandruff or hair-spray droplets. Nits are found firmly attached to the hair shaft. They are oval and usually yellow to white. Nits take about a week to hatch.

Nymph: The nit hatches into a baby louse called a nymph. It looks like an adult head louse but is smaller. Nymphs mature into adults about seven days after hatching. To live, the nymph must feed on blood.

Adult: The adult louse is about the size of a sesame seed, has six legs, and is tan to grayish-white in color. In people with dark hair, the adult louse looks darker. Females lay nits; they are usually larger than males. Adult lice can live up to 30 days on a person's head. To live, adult lice need to feed on blood. If the louse falls off a person, it dies within two days.

Where are head lice most commonly found?

Head lice are most frequently located on the scalp behind the ears and near the neckline at the back of the neck. Head lice hold on to hair with hook-like claws that are found at the end of each of their six legs. Head lice are rarely found on the body, eyelashes, or eyebrows. Continue Reading

Reviewed on 11/5/2015
References
REFERENCES:

American Academy of Pediatrics. "Pediculosis Capitis (Head Lice)." Red Book, 28th ed. Elk Grove Village, IL: American Academy of Pediatrics; 2009.

Chosidow, O. "Oral Ivermectin Versus Malathion Lotion for Difficult-to-Treat Head Lice." New England Journal of Medicine 362 Mar. 2010: 896-905.

Devore, C., and G. Schutze. American Academy of Pediatrics. "Head Lice. A Clinical Report: Guidance for the Clinician in Rendering Pediatric Care." Pediatrics 135.5 May 2015: e1355-1365.

Feldmeier, H. "Pediculosis Capitis: New Insights Into Epidemiology, Diagnosis and Treatment." Eur J Clin Microbiolo Infect Dis. Mar. 2012.

Frankowski, Barbara and Joseph A. Bocchini Jr. "Clinical Report: Head Lice, a Policy Update." Pediatrics 126.2 Aug. 2010: 392-403.

Gunning, K., K. Pippitt, B. Kiraly, and M. Sayler. "Pediculosis and scabies: treatment update." American Family Physician 86.6 Sept. 2012: 535-541.

United States. Centers for Disease Control and Prevention. "Head Lice." Sept. 24, 2013. <http://www.cdc.gov/parasites/lice/>.

IMAGES:

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4. "Male human head louse" by Gilles San Martin

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6. "Bugbuster" by Thanks for the polite permission of the Community Hygiene Concern, Joanna Ibarra

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