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Head Lice

Illustrations showing nit, adult louse, and scalp with nits attached

Lice are tiny insects about 1/4 inch in length. Head lice infect only the scalp. They make your scalp feel very itchy. Lice lay eggs that are called nits. They look like tiny white specs stuck to the hair. They don’t brush away or wash off like dandruff. Lice are easily spread by close contact with an infected person. They are also spread by sharing personal items such as hats, combs, brushes, towels, and bedding. Anyone can get head lice. You don't get head lice from dirty hair or poor hygiene. Lice can’t hop or fly, but they can crawl.

To live, adult lice must feed on blood. If lice fall off a person, they die within 1 to 2 days. They don’t spread disease.

Head lice symptoms include:

  • Feeling that something is crawling in your hair

  • Itching caused by an allergic reaction to the saliva of lice. (Itching alone doesn’t mean you have lice.)

  • Sores on your head (from scratching)

  • Seeing lice or nits

Home care

Head lice and nits don’t wash off by cleaning your hair with regular shampoo. Treatment is needed if you see live lice. There are medicine and nonmedicine treatments. If you only find nits, this doesn’t mean you have an active infection needing treatment. The nits can stay after the lice are dead and gone.

As you treat your head lice, also follow these steps:

  • Machine-wash all your hats, scarves, coats, bed linens, and towels in hot water.

  • Use your dryer’s hot cycle to dry these items. Dry clean any clothing, bed linens, or stuffed animals that can’t be washed this way. Or you can seal them in a plastic bag for 2 weeks. Lice will die during this time.

  • Combs, brushes, barrettes, hair ties, and curlers may be cleaned with a disinfectant or rubbing alcohol. Then rinse well with clean water.

  • Vacuum all rugs, carpets, car seats, and mattresses that were used while you were infected.

  • People who share the same bed should be treated at the same time to prevent reinfection. Household members who have signs of lice should also be treated.

  • Don't have sexual contact until rechecked by your healthcare provider to confirm that all lice are gone.

Medicine

Both prescription and over-the-counter medicines are available. These include medicated creams, lotions, or shampoos. Prescription pills are also available. Medicines may not always destroy the eggs or nits. A second treatment is usually advised 7 days later. If you see live lice after a second treatment, talk with your healthcare provider. Also talk with your provider if you find lice or nits in your eyebrows or eyelashes.

When treating lice with medicine:

  • Don't use the medicine around your eyes. If it gets in your eyes, wash them out thoroughly.

  • Don't use it inside your nose, ear, mouth, vagina, or on your eyebrows or eyelashes.

  • Pregnant or breastfeeding women and children younger than 2 years old should not use it until discussing it with your provider.

If your healthcare provider advises a medicine, use it as follows, or as directed by the medicine label:

  1. Wash your hair with your regular shampoo. Don't use conditioner or combination shampoo/conditioner before using the lice medicine. They may make the medicine less effective.

  2. Rinse with water and then towel dry. The towel will need to be washed, as there could be lice on it.

  3. Put enough of the medicated cream rinse in to soak the entire hair and scalp area. This includes behind the ears and the back of the neck.

  4. Rinse well after 10 minutes, or as directed on the medicine label. Leaving it on longer will not make it work better. When rinsing, limit the amount of medicine that gets on the skin of the rest of your body.

  5. Once you have washed the medicine out of the hair, use a special fine-toothed comb called a nit comb. This is designed to remove the lice and nits.

  6. Stroke the comb through one section of hair at a time. Go from scalp to hair tip, cleaning the comb after each stroke.

  7. Put clean clothes on after the treatment.

  8. Continue to check the hair for 2 to 3 weeks to make sure the lice are gone.

Nonmedicine treatment

Medicines are usually the most effective treatment. But if you don't want to use chemicals, there is a treatment called wet combing. This is a longer process. It can take as much as an hour each time to do it thoroughly. A special nit comb is needed.

Since no medicine was used to kill the lice, you will need to wet comb your hair a few times. Follow these steps:

  1. Wash your hair as usual, using your regular shampoo.

  2. Put on lots of conditioner.

  3. Use a regular comb to untangle and straighten your hair.

  4. Switch to the nit comb. Stroke the comb carefully through your hair. Go from the scalp to the tips of the hair.

  5. Remove any lice or nits by wiping or rinsing off the comb.

  6. Do this through every part of your hair. Do a small area at a time. Don't miss any section.

  7. When finished, rinse out the conditioner. Repeat the combing 3 more times.

Note: Repeat the wet-combing process every 3 to 4 days. Keep doing this until you don't see lice for 3 sessions in a row.

Medicines to treat symptoms

Itching probably causes the most discomfort. If you were not given a prescription antihistamine, then you may use an over-the-counter version to reduce itching if large areas of the skin are involved. Over-the-counter antihistamines that have diphenhydramine are sold at pharmacies and grocery stores. Use an antihistamine in pill form, not a cream. . This medicine may make you sleepy. So use lower doses during the day and higher doses at bedtime. Some antihistamines won’t make you so sleepy. They are a good choice for daytime use. Note: Don’t use medicine that has diphenhydramine if you have glaucoma. Also don’t use it if you have trouble urinating due to an enlarged prostate.

You may be given antibiotics for a bacterial infection. This is usually caused by scratching the scalp. Take the antibiotics as directed by your healthcare provider until they are finished. Keep taking them even if the wound looks better. This helps make sure that the infection has cleared.

Prevention

To prevent getting lice again:

  • Don't share clothing, towels, brushes, combs, hats, scarves, coats, or hair accessories with other people.

  • Stay away from hair-to-hair contact with other people

Follow-up care

Follow up with your healthcare provider, or as advised. Call your provider if you still have itching on your scalp or see live lice in your hair 7 days after the first treatment.

When to get medical advice

Call your healthcare provider right away if any of the following occur:

  • Itching gets worse and antihistamines don't help

  • Scalp becomes swollen or tender

  • Scalp sores are draining pus (a creamy yellow or white liquid)

  • Hair becomes matted or smells bad

  • Other signs of infection, like increasing redness, swelling, pain, or pus drainage

  • Trouble breathing

Online Medical Reviewer: Jessica Gotwals BSN MPH
Online Medical Reviewer: Michael Lehrer MD
Online Medical Reviewer: Ronald Karlin MD
Date Last Reviewed: 3/1/2022
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