Ways to Treat Head Lice

Head lice are insects with six claws and no wings that cannot hop or fly. Lice move by crawling; their claws hold tightly onto hair. They're gray-white or tan and the size of sesame seeds, and they feed on human blood four or five times a day. Lice live and breed within a quarter inch of the hair from the base of the scalp, especially near the ears and neck. Head lice may also thrive in eyebrows and beards. Lice are most active at night.

Head lice are very contagious, and they spread by direct contact with someone who is infested or by sharing clothing (like hats) with someone who has lice. Female lice attach their eggs firmly to hair. Lice eggs are called nits, which are usually yellow to white -- these are extremely small and can be confused with dandruff. Nits hatch in eight or nine days, and they reach adult size nine to 12 days after hatching. Lice live up to 30 days. Females can lay 50 to 150 eggs in their lifetime. If lice fall off the scalp, they die within two days.

Six to 12 million children, mostly between 3 and 12 years of age, get lice each year. It's more common in girls and in individuals living in crowded conditions. Head lice is less common in African-Americans.

[Read: How to Get Rid of Lice .]

How Can I Tell if My Child Has Head Lice?

The first symptom of head lice is intense itching. Other symptoms include a tickling sensation or a feeling that something is moving in the hair. Small red bumps on the scalp or neck may also be present (Table 1). Constant scratching can result in open wounds and infections.

Myths and Facts

Myth: Pets spread head lice.

Fact: Lice cannot live on pet fur.

Myth: Head lice carry diseases.

Fact: Lice do not carry other diseases.

Myth: Head lice thrive in dirty households.

Fact: The cleanliness of a person or house has no role in spreading head lice.

Myth: Insect sprays kill lice.

Fact: Insect sprays should never be used. They may contain harmful chemicals.

Myth: Swimming spreads lice.

Fact: Lice tightly hold onto hair when underwater. Chlorine in pool water cannot kill lice.

[See: Pharmacists' Top Recommended Dandruff Shampoos.]

Head lice are treated with OTC products containing pyrethrins. Rid and Nix are brand names of products containing pyrethrins (Table 2). Common side effects of pyrethrins are skin irritation and the feeling that the scalp is burning and itchy. People allergic to ragweed or chrysanthemums should avoid pyrethrins.

Two treatments spaced seven to nine days apart usually get rid of lice. The second treatment is needed to kill nits that have hatched after the first treatment. Because products may not kill all the nits, you should continue to comb for nits for at least two weeks following the second treatment. Some lice are resistant to treatment. Your doctor can prescribe a cream, lotion or shampoo that kills resistant lice. There is some evidence that tea tree oil and lavender oil are effective against lice. While the American Medical Association recommends tea tree oil, the National Institutes of Health does not recommend herbal treatments.

If you want to avoid medications, the following methods are recommended for treating head lice.

Apply an oil (like cooking oil) or petroleum jelly to wet hair. Using a lice comb, remove nits and lice. Comb the hair for 30 minutes every two or three days for a two-week period.

Remove all hair by shaving the entire head and neck. Lice die if they cannot attach to hair.

[See: Pharmacists' Top Recommended Lice Treatments.]

Prevention

Teach your children about head lice and ways to prevent it (Table 3).

Note: This article was originally published on Aug. 4, 2014 on PharmacyTimes.com. It has been edited and republished by U.S. News. The original version, with references, can be seen here.