What are head lice?
Head lice are tiny insects that live close to the scalp, where they lay and attach their eggs (nits). Lice can't survive unless they are close to the scalp.
- Live lice are tan to grayish white. They're about the size of a sesame seed. It may be easiest to find them on the back of the neck at the hairline or behind the ears.
- Nits look like tiny yellow or white dots attached to the hair, close to the scalp. They're often easier to see than live lice. Nits may look like dandruff. But you can't pick them off with your fingernail or brush them away.
Head lice are most common in children. They can spread anytime a child's head comes into contact with the head or hair of someone who has lice. Lice can't fly or jump.
Head lice aren't dangerous. They don't spread disease or have anything to do with how clean someone is.
What are the symptoms?
Head lice may cause an itchy feeling on the scalp. This is because of your body's reaction to the lice bites. But not everyone has itching, and not all itching means you have lice. Lice can be on the scalp for 4 to 6 weeks before itching starts.
How are they diagnosed?
You can check for head lice at home. Use a fine-toothed comb. Part small sections of hair in a place with good light. Using a magnifying glass can help. You can also check with a doctor, who will ask about symptoms and check the scalp and hair for lice and nits.
How are head lice treated?
There are several over-the-counter medicines that kill lice. Most of them are creams or shampoos that you put on the scalp. There are also prescription medicines. Each type of medicine is a little different, so it's important to follow the directions carefully. Your doctor or pharmacist can answer any questions you may have.
How can you care for yourself at home?
- Use an over-the-counter medicine to kill lice. Your doctor or pharmacist can help you choose a medicine that is safe.
- Follow the directions that come with the medicine carefully. Some medicines should only be used once. Others require a second treatment 7 to 9 days after the first treatment. Don't use more medicine than you should or two medicines at the same time.
- Do not shampoo or condition your hair before you use the medicine. It's best to wait 1 to 2 days after you use the medicine before washing your hair.
- To rinse out the medicine, use warm (not hot) water. Make sure to wash out the medicine over the sink instead of the shower. This helps to avoid some of the medicine coming into contact with your skin.
- Check your scalp for live, active lice 12 hours after treatment. If you find some, talk to your doctor. You may need a different type of treatment.
- Try wet-combing, which may help remove lice and nits. Use a comb with teeth that are close together. A flea comb that's made for dogs and cats will also work. Wet the hair. Comb all of the hair very carefully. Combing needs to be done over and over.
- Try not to scratch. Scratching can cause sores on the scalp, which can lead to an infection. It may help to use an over-the-counter anti-itch cream to calm the itching. If the itching is really bad, ask the doctor about an over-the-counter antihistamine. Read and follow all instructions on the label.
How can you prevent head lice?
- Check everyone in your home for lice. If your child shares a bed with someone, the other person should be treated too. (Don't worry about pets. They can't get lice.)
- Teach your children not to share anything that comes into contact with hair. For example, don't share hair bands, towels, helmets, hats, combs, or brushes.
- You don't need to spend a lot of time or money deep cleaning your home. But it's a good idea to:
- Soak hairbrushes, combs, barrettes, and other items for 10 minutes in hot water (at least 130 °F [54.4 °C]).
- Machine-wash clothes, bedding, towels, and hats that touched the head in the last 2 days in hot water (at least 130 °F [54.4 °C]). Dry them in a hot dryer. If you don't have access to a washing machine or if items can't be washed or dried, store these items in a sealed plastic bag for 14 days.
- Vacuum carpets, mattresses, couches, and other upholstered furniture.
Current as of: March 21, 2023
Author: Healthwise Staff
Clinical Review Board: All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.