Head lice, the most common type of lice, are tiny parasitic insects that survive by feeding on human blood. Head lice are most commonly found on the scalp, behind the ears and near the neckline at the back of the neck. Head lice are rarely found on the body, in the eyebrows, or eyelashes. They can lay up to six eggs (nits) a day that attach to strands of hair close to the scalp. Head lice are wingless, cannot fly or jump, and they do not burrow under the skin. However, they can crawl, sometimes rapidly.
Lice are spread by direct contact with an infested person’s head or personal belongings such as combs, brushes, and hats. They can also be spread by unwashed clothing, bedding, or towels. Head lice are commonly found in more than one person in the same household. Children often spread head lice during close contact while playing. A person can also get head lice by lying on a bed, couch, pillow, carpet, or stuffed animal that has been in direct contact with an infested person. Pets cannot spread head lice.
Anyone who comes in close contact (especially head-to-head contact) with someone who already has head lice is at greatest risk. Preschool and elementary school-age children (3-11 years of age) and their families are infested most often. Girls and women get head lice more often than boys and men. In the United States, African-Americans rarely get head lice. Personal hygiene or cleanliness in the home or school has nothing to do with getting head lice.
The main symptom of head lice is itching. The scalp may appear red from scratching. Sometimes an infested person has a tickling feeling of something moving in the hair. Lice and nits can be seen on the hair; identification is usually made by detecting nits attached to the hair close to the scalp. Nits are tiny, grey-white oval specks that do not come off the hair easily, like a piece of dandruff would. Nits found within ¼ inch from the scalp are usually alive and treatment is needed. Using a flashlight, adult lice can be seen by separating hair at the base of the neck or around the ears.
Often, head lice can be treated with over-the-counter medications. Prescription drugs are also available. Consult your pharmacist or health care provider is you are unsure about which medication to use.
In addition to treatment of the infested person(s), the following actions can assist with control:
Do not use hairbrushes, combs, or hats that belong to other people.
If infested, use treatment medications as directed. Re-infestation occurs often and can be frustrating for parents, teachers, and children. Treating re-infested and newly infested cases at the same time may help stop the cycle.
For additional information on head lice, please visit the Centers for Disease Control and Prevention (CDC) Web site at http://www.cdc.gov/ncidod/dpd/parasites/lice/default.htm or the Harvard School of Public Health Web site at http://www.hsph.harvard.edu/headlice.html.
