Head lice are parasitic wingless insects. They live on people's heads and feed on their blood.
An adult louse is about the size of a sesame seed. The eggs, called nits, are even smaller - about the size of a knot in thread. Lice and nits are found on or near the scalp, most often at the neckline and behind the ears.
Lice spread by close person-to-person contact. It is possible, but not common, to get lice by sharing personal belongings such as hats or hairbrushes.
Children ages 3-11 and their families get head lice most often. Personal hygiene has nothing to do with getting head lice. Head lice do not spread disease.
Never share hair brushes, combs, hair pieces, hats, bedding, towels, or clothing with someone who has head lice.
If your child has lice, be sure to check policies at schools and daycare. Many places do not allow infected children to be at school until the lice have been completely treated.
Some schools may have policies to make sure the environment is clear of lice. Cleaning of carpets and other surfaces often helps prevent spread of all types of infections, including head lice.
Head lice infect hair on the head. Tiny eggs on the hair look like flakes of dandruff. However, instead of flaking off the scalp, they stay in place.
Head lice can live up to 30 days on a human. Their eggs can live for more than 2 weeks.
Head lice spread easily, particularly among school children. Head lice are more common in close, overcrowded living conditions.
You can get head lice if you:
- Come in close contact with a person who has lice
- Touch the clothing or bedding of someone who has lice
- Share hats, towels, brushes, or combs of someone who has lice
Having head lice causes intense itching, but does not lead to serious medical problems. Unlike body lice, head lice never carry or spread diseases.
Having head lice does NOT mean the person has poor hygiene or low social status.
Symptoms of head lice include:
- Very bad itching of the scalp
- Small, red bumps on the scalp, neck, and shoulders (bumps may become crusty and ooze)
- Tiny white specks (eggs, or nits) on the bottom of each hair that are hard to get off
Most of the time, lice are killed with the proper treatment. However, lice can come back if you do not get rid of them at the source.
Lotions and shampoos containing 1% permethrin (Nix) often work well. You can buy these medicines at the store without a prescription. If these products do not work, a doctor can give you a prescription for stronger medicine. Always use the medicines exactly as directed. Using them too often or in the wrong way can cause side effects.
To use the medicine shampoo:
- Rinse and dry the hair.
- Apply the medicine to the hair and scalp.
- Wait 10 minutes, then rinse it off.
- Check for lice and nits again in 8 to 12 hours.
- If you find active lice, talk to your health care provider before doing another treatment.
You also need to get rid of the lice eggs (nits) to keep lice from coming back.
To get rid of nits:
- You can use products that make the nits easier to remove. Some dishwashing detergents can help dissolve the "glue" that makes the nits stick to the hair shaft.
- Remove the eggs with a nit comb. Before doing this, rub olive oil in the hair or run the metal comb through beeswax. This helps make the nits easier to remove.
- Metal combs with very fine teeth are stronger and work better than plastic nit combs. These metal combs are easier to find in pet stores or on the Internet.
- Comb for nits again in 7 to 10 days.
When treating lice, wash all clothes and bed linens in hot water with detergent. This also helps prevent head lice from spreading to others during the short period when head lice can survive off the human body.
Ask your provider if people who share bedding or clothes with the person who has head lice need to be treated as well.