Medical Health Encyclopedia

Head lice


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Head lice
Head lice
Head louse, male
Head louse, male
Head louse emerging from egg
Head louse emerging from egg
Head louse - female
Head louse - female
Head louse infestation - scalp
Head louse infestation - scalp
Lice, head - nits in the hair with close-up
Lice, head - nits in the hair with close-up
Nit on human hair
Nit on human hair
Overview Symptoms Treatment Prevention
Definition

Head lice are tiny insects that live on the skin covering the top of your head, called the scalp. Lice can be spread by close contact with other people.

Head lice may also be found in eyebrows and eyelashes.

See also:


Alternative Names

Lice - head; Nits; Pediculosis capitis - head lice


Causes, incidence, and risk factors

Head lice infect hair on the head. Tiny eggs on the hair look like flakes of dandruff. However, instead of flaking off the scalp, they stay put.

Head lice can live up to 30 days on a human. Their eggs can live for more than 2 weeks.

Head lice spread easily, particularly among school children. Head lice are more common in close, overcrowded living conditions.




You can get head lice if you:

  • Come in close contact with a person who has lice
  • Touch the clothing or bedding of someone who has lice
  • Share hats, towels, brushes, or combs of someone who has had lice

Having head lice does NOT mean the person has poor hygiene or low social status.

Having head lice causes intense itching, but does not lead to serious medical problems. Unlike body lice, head lice never carry or spread diseases.



Review Date: 01/24/2011
Reviewed By: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org).

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