Medical Health Encyclopedia

Head lice

Injury Disease Nutrition Poison Symptoms Surgery Test Special Topic

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

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

Overview Symptoms Treatment Prevention

Head lice

Definition:

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

Alternative Names:
Lice - head; Nits; Pediculosis capitis - head lice

Causes, incidence, and risk factors:

Text Continues Below

---

There are three common types of lice: head lice, body lice, and pubic lice (also called crabs). Head lice infect the scalp hair and are easiest to see at the nape of the neck and over the ears. Tiny eggs can be seen on the hair, appearing much like flakes of dandruff, but stuck firmly to the hair shaft instead of flaking off the scalp.

Lice can also live on clothing, carpets, or bedding.

Head lice are spread easily and cause intense itching, but they do not lead to a serious medical problem. Lice are more common in close, overcrowded living conditions. Lice spread readily among school children.

Having lice is NOT an indicator of poor hygiene or low social status.

References:

Long SS, Pickering LK, Prober, CG, eds. Principles and Practice of Pediatric Infectious Diseases. 2nd Ed. New York, NY: Churchill Livingstone, 2003.

Mandell GL, Bennett JE, Dolin R, eds. Principles of Infectious Diseases. 5^th Ed. New York, NY: Churchill Livingstone, 2000:2972-2973.

Goetz CG, Pappert EJ. Textbook of Clinical Neurology. 2^nd Ed. Philadelphia, PA: Saunders; 2003.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 2004 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.