Head Lice

What are head lice?

Head lice are tiny insects that live on the scalp and hair. Occasionally, head lice can be found in the eyebrows and eyelashes. Head lice are parasites that live off human blood. They feed by biting the scalp, which leads to intense itching.

When you have head lice, it is called pediculosis. The adult insect is called a louse and is about the size of a large grain of sand. Because they are so small, head lice can be hard to spot. Head lice eggs (nits), though even smaller, are attached to the base of hair shafts and are easier to find. The nits resemble dandruff flakes, but they aren’t easily brushed off like dandruff flakes. Instead, they stay attached to the hair shaft until you pick them off. Nits are easiest to spot around the neck and ears in bright sunlight or with a very bright light. The adult louse can live on the scalp for about 30 days and the nits can survive for two weeks on a hair shaft.

Lice do not have wings and do not hop or jump, but they are able to crawl very quickly. This allows them to spread easily and quickly through close contact with someone who is infested. You can also get head lice from sharing hairbrushes, combs, hats, scarves, hair accessories, towels, pillows, beds, or stuffed animals with someone who is already infested. Frequent bathing and hair washing with general shampoos does not prevent or cure head lice. Therefore, having head lice is not a sign of poor personal hygiene.

Although anyone can get head lice, it most commonly occurs in children three to 12 years of age. In the United States, approximately six to 12 million children have head lice infestations each year (Source: AAP). Children of this age tend to play closely with each other and share items that can transfer head lice. Adults and family members of infested children should be checked for head lice and treated if necessary.

The main symptoms of head lice are intense scalp itching; a tickling or crawling sensation on the scalp; small red bumps or sores on the scalp, neck or shoulders; and the presence of nits. Because head lice are most active in the dark, itching can disturb your sleep.

Head lice can be treated and cured. Both over-the-counter (OTC) and prescription products are available to treat head lice. Always talk with your doctor before using any of the OTC products because they contain pesticides that may be harmful for certain people, including women who are pregnant or nursing and people with asthma or allergies. It is unlikely that any of these products will kill all the nits, so an important part of treatment is using a nit comb to remove the nits. You will also need to use hot water to wash any articles that came in contact with the infested person, including pillows, bed linens, towels, and stuffed animals.

Head lice do not carry or spread disease and usually do not lead to serious complications. However, a secondary skin infection with bacteria and other germs can occur from scratching the scalp. Seek prompt medical care if you have any symptoms of head lice, symptoms continue after home treatment, or you have red, tender skin on the scalp, which may be a sign of infection.