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Head Lice

What is head lice?

Head lice are tiny, gray bugs. They are 2 to 3 millimeters long. They move fast and are hard to see. Head lice live in the hair and bite the scalp to suck blood.

They attach their white eggs, called nits, to the hair. Unlike dandruff, nits can't be shaken off. The nits are easier to see than the lice because they are white and there are a lot of them.

The back of the neck is the favorite area for lice and nits. Lice and nits cause your child's scalp to itch and have a rash.

What is the cause?

Head lice live only on human beings. They can be spread quickly by using the hat, comb, or brush of an infected person, or simply by close contact. Lice may crawl or fall onto clothing, bedding, towels, or furniture. Anyone can get lice despite good health habits and frequent hairwashing. The nits (eggs) normally hatch into lice in about 1 week.

How can I take care of my child?

  • Anti-lice shampoo or rinse

    Your child's anti-lice shampoo is _____________________.

    Follow the directions. Most products must be used on dry hair. Pour about 2 ounces of the anti-lice shampoo into the dry hair. Add a little warm water to work up a lather. Scrub the hair and scalp for 10 minutes, by the clock. Rinse the hair thoroughly and dry it with a towel. The shampoo kills both the lice and the nits. Repeat the anti-lice shampoo once after 7 days to prevent reinfection.

  • Removing nits

    To make sure the nits are dead, wait at least 8 hours after using the shampoo before removing them.

    Remove the nits by backcombing with a fine-tooth comb or pulling them out individually. The nits can be loosened using a mixture of half vinegar and half water. Apply the mixture to the hair and keep your child's hair under a towel wrap for 30 minutes. Even though the nits are dead, most schools will not allow children to return if nits are present. The head does not need to be shaved to cure lice.

  • Lice in the eyelashes

    If you see any lice or nits in the eyelashes, put plain petroleum jelly on the eyelashes twice a day for 8 days. The lice won't survive.

  • Cleaning the house

    Head lice can't live for more than 24 hours off the human body. Your child's room should be vacuumed. Soak combs and brushes for 1 hour in a solution made from the anti-lice shampoo. Wash your child's sheets, blankets, and pillowcases in hot water. Items that can't be washed (hats or coats) can be sealed in plastic bags for 2 weeks (the longest that nits can survive). You do not need to use anti-lice room sprays.

  • Contagiousness

    Check the head of everyone else living in your home. If lice or nits are seen, or they start to get an itchy scalp rash, they should be treated with anti-lice shampoo. Bedmates of children with lice should also be treated. If in doubt, have the person checked. Your child can return to school after the first treatment with the shampoo. Remind your child not to share combs and hats.

How long does it last?

After you use anti-lice shampoo all lice and nits will be killed. If the lice come back, it usually means your child has had contact with another infected person or the shampoo wasn't left on for 10 minutes. There are no lasting problems from having lice and they do not carry other diseases.

When should I call my child's health care provider?

Call during office hours if:

  • The rash and itching are not gone 1 week after treatment.
  • The sores start to spread or look infected.
  • The lice and nits return.
  • You have other questions or concerns.
Written by B.D. Schmitt, M.D., author of "Your Child's Health," Bantam Books.
Published by McKesson Provider Technologies.
Last modified: 2006-03-02
Last reviewed: 2006-03-02
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
Copyright 2006 McKesson Corporation and/or one of its subsidiaries. All Rights Reserved.
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