Head Lice

Also called Pediculus humanus capitis, head lice are parasitic insects found on the heads of people. Having head lice is very common. Anyone who comes into close contact with someone who already has head lice, contaminated clothing, and other belongings is at risk for getting head lice.

There are three forms of lice: the nit, the nymph, and the adult.

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Nits: Nits are head lice eggs. They are hard to see and are often confused with dandruff or hair spray droplets. Nits are found firmly attached to the hair shaft. They are oval and usually yellow to white. Nits take about 1 week to hatch.

Nymph: The nits hatch into baby lice called nymphs. They look like adult lice, but are smaller. Nymphs mature into adults about 1 week after hatching. To live, the nymph must feed on blood.

Adult: The adult louse is about the size of a sesame seed, has six legs, and is tan to grayish-white. In persons with dark hair, the adult louse will look darker. Females lay nits and are usually larger than the males. Adult lice can live up to 30 days on a person's head. To live, adult lice need to feed on blood. If a louse falls off a person, it dies within two days.

Head lice are most commonly found behind the ears and near the neckline at the back of the neck. Head lice hold onto hair with hook-like claws found at the end of each of their legs. Head lice are rarely found on the body, eyelashes, or eyebrows.

Signs and Symptoms
Signs and symptoms of a head lice infestation are tickling feeling of something moving in the hair, itching (caused by an allergic reaction to the bites), irritability, and sores on the head caused by scratching. These sores can sometimes become infected.

Treatment
There are several over-the-counter treatments for head lice. Follow the directions supplied with the treatment kit. Following treatment, most nits will still be attached to hair shafts. Nits may be removed with fingernails or comb provided in treatment kit. To kill any lice and nits that may be left on clothing or bedding, machine wash those washable items that the infested person used during the 2-3 days before treatment. Use the hot water cycle (130o F) of the washing machine to wash clothes. Use the hot cycle of the dryer for at least 20 minutes to dry clothes. Dry clean clothing that is not washable. Retreat in 7-10 days if lice are still found.

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