Head lice

Definition

Head lice are tiny insects that live on the scalp. They can be spread by close contact with other people.

These lice only live in hair and occasionally eyebrows and eyelashes.

See also:

• Body lice
• Pubic lice

Alternative Names

Causes

Head lice infect hair on the head. They are easiest to see on the neck and over the ears. Tiny eggs on the hair look like flakes of dandruff. However, instead of flaking off the scalp, they stay put.

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

Head lice spread easily. You can get head lice when you come in close contact with a person who has lice, or by touching their clothing or bedding. Head lice are more common in close, overcrowded living conditions. Lice spread easily among school children.

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.

References

Long SS, Pickering LK, Prober, CG. Principles and Practice of Pediatric Infectious Diseases. 2nd ed. Philadelphia, Pa: Elsevier; 2003.

Mandell GL, Bennett JE, Dolin R. Principles of Infectious Diseases. 6th ed. London: Churchill Livingstone; 2005.

Goetz CG, Pappert EJ. Textbook of Clinical Neurology. 2nd ed. St. Louis, Mo: WB Saunders; 2003.

Goldman L, Ausiello D. Cecil Textbook of Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007.