Pediatrics Common Questions, Quick Answers

Head Lice (Pediculosis)

Donna D'Alessandro, M.D.
Lindsay Huth, B.A.
Peer Review Status: Internally Reviewed
Creation Date: December 2001
Last Revision Date: April 2002

Common Questions, Quick Answers

• What are head lice?
• What causes head lice?
• Who can get head lice?
• What are the symptoms of head lice?
• Is head lice contagious?
• How is head lice treated?
• How long does head lice last?
• Can I prevent it?
• When should I call the doctor?

What are head lice?

• Head lice are small insects that lay eggs (nits) on people's scalp.
• After 7-8 days, the eggs hatch.
• The empty eggshells look like small grains of rice that stick to the hair.

What causes head lice?

• You do not get lice because you are dirty or unclean.
• Lice are passed from person to person by contact with infested persons or items.

Who can get head lice?

• Anyone can get head lice.
• Having head lice is common for school-age children.
• Pets can't get lice.

What are the symptoms of head lice?

• Since lice are hard to see, you can tell if your child has lice by checking the hair for nits.
• Comb through the hair to look for nits. You can use a magnifying glass to help you.
• Nits stick to the hair while things like dandruff and dried hairspray flakes can be blown away.
• Nits could be on the scalp, in the hair, behind the ears, or at the back of the neck near the neckline.
• Lice will cause an itchy scalp.
• It feels like things are tickling the head or crawling through the hair.
• Children who have lice will often scratch at their heads, creating sores.
• Infected sores will get crusty, ooze, and may cause swollen glands at the back of the neck.

Is head lice contagious?

• Yes. Head lice is contagious.
• Lice cannot jump or fly. Pets can't spread lice.
• Lice are passed from person to person by sharing clothes, brushes, pillows, toys, etc.
• To kill the lice, wash these items in hot water, put them in a hot dryer for 30 minutes, or take them to the dry cleaners.
• Soak combs and barrettes in hot water for 15 minutes.
• Seal items that can't be washed in plastic bags for 10-14 days. Lice will die after about one week off the scalp.
• Vacuum floors and furniture.
• Do not spray your house with chemicals. It can be dangerous to your health.
• Tell your child's school or day care if your child has lice. Other children should be checked and treated if needed.

How is lice treated?
Lice can be treated by combing or with medicated shampoos. Only use treatment if you are sure the person has lice. Don't treat others "just in case." If your child is under 2 years old, call the doctor. Older children can be treated at home without seeing a doctor.

Combing

• Removing nits is the best choice for cure.
• First, soak the hair in nit-removal lotion bought from the store or use a mix of half-water and half vinegar.
• Next, use a fine-toothed comb to remove the nits. The Licemeister comb is available at stores. A flea comb for pets also will work.
• Separate your child's hair and comb small areas toward the scalp.
• This method is called "back-combing" and is the least painful treatment.

Medicated Shampoos

• Lice can be treated with medicated shampoos.
• Medicated shampoos can be bought at the store without a prescription.
• Common shampoos are A-200, Pronto, R&C, Triple X, Nix, and Rid.
• To choose a shampoo not listed here, look for the active ingredient Permethrin 1%.
• Each shampoo has different directions. Follow the directions closely, especially for children under age 2.
• Repeat treatment after one week to make sure all the lice and nits are dead.
• Do not shampoo more than 3 times.
• The scalp might be itchy for one week after shampoo treatment.
• Do not soak your child's hair with gasoline or kerosene. It is not safe.

How long does head lice last?

• Your child can return to school or daycare the day after treatment.
• Continue to check your child's hair for nits.
• If nits are as close as 3/8 of an inch to the scalp, your child has active lice.
• If nits are further away than 3/8 inch from the scalp, your child has an old infection.

Can I prevent it?

• You can prevent the spread of lice.
• Wash personal and household items as described above.
• Warn your children not to share combs, hats, and other items with an infested person.
• Shaving your child's head or cutting his hair will not prevent lice or make the infection better.

When should I call the doctor?

• Call the doctor if your child is under 2 years old and you think he has lice.
• Call the doctor if you aren't sure if your child has lice.
• Call the doctor if treatment doesn't get rid of the lice.
• Call the doctor if your child has infected sores that are tender and do not heal.
• Call the doctor if you have questions about your child's illness or treatment.
• Call the doctor if others in your house begin to have itchy scalps.

Quick Answers

• Head lice are small insects that lay eggs (nits) on people's scalp.
• You do not get lice because you are dirty or unclean.
• Anyone can get head lice.
• You can tell if your child has lice by checking his hair for nits. Lice will also cause an itchy scalp.
• Head lice is contagious. Lice are passed from person to person by contact with infested persons or items.
• Lice can be treated by combing or with medicated shampoos.
• Your child can return to school or daycare the day after he has been treated.
• You can prevent the spread of lice by washing personal and household items.
• Call the doctor if your child is less than 2 years old and you think he has lice.

References

• Iowa Department of Public Health: Information for the Health Professional. Fact Sheet: Lice. 1998 Sept .
• MedlinePlus. Head Lice. 2001 July 2 (cited 2001 July 5) URL: http://www.nlm.nih.gov/medlineplus/headlice.html
• Lane AT M.D. Head Lice (Cooties). Pediatric Infectious Diseases Journal (cited 2001 July 5)

See related Patient Topics Child and Teen Health, Food, Nutrition and Metabolism, Head Lice, Infections, School Health or Skin, Hair and Nails.

See related Provider Topics Child and Teen Health, Food, Nutrition and Metabolism or Infections.

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