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Head Lice

What Are Head Lice?

Head lice are tiny, wingless parasitic insects. They live among human hairs and feed on tiny amounts of blood drawn from the scalp.

Head lice are a common problem, especially for kids. They're contagious, annoying, and sometimes tough to get rid of. Their bites can make a child's scalp itchy and irritated, and scratching can lead to infection. But on their own, lice aren't dangerous and don't spread disease.

It's best to treat head lice right away because they spread easily from person to person.

What Are the Signs & Symptoms of Head Lice?

Even though they're tiny, you can see head lice. Here are things to look for:

  • Lice eggs (called nits). These look like tiny yellow, tan, or brown dots before they hatch. Lice lay nits on hair shafts close to the scalp, where the temperature is perfect for keeping warm until they hatch. Nits look a bit like dandruff, but aren't removed by brushing or shaking them off.

    Unless a child has many head lice, it's more common to see nits in the hair than live lice crawling on the scalp. Lice eggs hatch 1–2 weeks after they're laid. After hatching, the remaining shell looks white or clear and stays attached to the hair shaft. This is when it's easiest to spot them, as the hair is growing longer and the egg shell is moving away from the scalp.Head lice adult and nit on hair
  • Adult lice and nymphs (baby lice). Adult lice are no bigger than a sesame seed and are grayish-white or tan. Nymphs are smaller and become adult lice about 1–2 weeks after they hatch. If head lice isn't treated, this process repeats itself about every 3 weeks. Most lice feed on blood several times a day, and they can survive up to 2 days off the scalp.
  • Scratching. With lice bites come itching and scratching. This is due to a reaction to the saliva (spit) of lice. But the itching doesn't always start right away. It depends on how sensitive a child's skin is to the lice. It can sometimes take weeks for kids with lice to start scratching. They may complain, though, of things tickling or moving around on their heads.
  • Small red bumps or sores from scratching. Some kids have mild irritation from scratching, while others may get a bothersome rash. Scratching a lot can lead to a bacterial infection. Watch for swollen lymph glands and red, tender skin that might have crusting and oozing. Doctors may treat these infections with an oral antibiotic.

How Can I Check My Child for Head Lice?

To check for lice or nits, part your child's hair into small sections. Use a fine-tooth comb to check for lice and nits on the scalp, behind the ears, and around the nape of the neck. It's rare for lice to be in eyelashes or eyebrows.

A magnifying glass and bright light may help. But it can be tough to find a nymph or adult louse. Often, there aren't many of them and they move fast.

Also check with your child's school nurse or childcare center director to see if other kids are being treated for lice. If your child does have lice or nits, tell the staff and find out what their policy is on kids returning. Most let kids return after they've had one topical treatment for lice

How Are Head Lice Treated?

See your doctor if your child is scratching his or her head or complains of an itchy scalp that won't go away. The doctor can tell you if your child has lice and needs treatment.

The doctor can recommend a medicated shampoo, cream rinse, or lotion to kill the lice. These may be over-the-counter (OTC) or prescription medicines. Medicated lice treatments usually kill the lice, but it may take a few days for the itching to stop. For very resistant lice, an oral medicine (taken by mouth) might be prescribed.

Be sure that the medicine is safe for your child's age. While over-the-counter shampoos are safe for kids as young as 2 months, other medicines are safe only for kids 2 years and older. Follow the directions because these products are insecticides. Applying too much — or using it too often — can be harmful.

Treatment may not work if the lice are resistant to it. So your doctor may suggest combing out the nits with a fine-tooth comb and repeating treatment in 7 to 10 days to kill any newly hatched nits.

Removing By Hand

If your child is 2 months old or younger, you should not use medicated lice treatments. Instead, remove the nits and lice by hand.

To do this, use a fine-tooth comb on wet, conditioned hair every 3 to 4 days for 3 weeks after the last live louse was seen. Wetting the hair temporarily stops the lice from moving, and the conditioner makes it easier to get a comb through the hair.

There's no need to buy electronic combs that claim to kill lice or make nits easier to remove. No studies have been done to back up these claims. You also don't need to buy special vinegar solutions to apply to the scalp before picking nits. Water works fine.

Wet combing is also an alternative to pesticide treatments in older kids. Though petroleum jelly, mayonnaise, or olive oil are sometimes used to try to suffocate head lice, these treatments may not work. If medicine doesn't work and you want to try these methods, talk to your doctor first.

Remove nits carefully every week for at least 3 weeks in a row, and watch your child closely to see if any live lice return.

Treatment Dont's

There are some things you should not do when kids are being treated for head lice:

  • Don't use a hairdryer on your child's hair after applying scalp treatments because some contain flammable ingredients. A hair dryer also could send live lice into the air and spread them to others nearby.
  • Don't use a conditioner or shampoo/conditioner combination before applying lice medication.
  • Don't wash your child's hair for 1 to 2 days after using a medicated treatment.
  • Don't use sprays or hire a pest control company to try to get rid of the lice. These treatments can be harmful. Head lice don't survive long after they fall off a person, so you don't need to spend a lot of time and money trying to rid the house of lice.
  • Don't use the same medicine more than three times on one person. If it doesn't seem to be working, your doctor may recommend another medicine.
  • Don't use more than one head lice medicine at a time.
  • Don't use essential oils (such as ylang ylang oil or tea tree oil) to treat lice on the scalp. These oils can cause allergic skin reactions and aren't approved by the U.S. Food and Drug Administration (FDA). Also, no studies have shown whether such treatments work.
  • Don't use chemicals such as gasoline or kerosene on the hair. These are highly flammable and should never be used on anyone.

Are Lice Contagious?

Lice are highly contagious and spread quickly from person to person, especially in group settings like schools, childcare centers, slumber parties, sports activities, and camps.

They can't fly or jump, but these tiny parasites have claws that let them crawl and cling to hair. They spread through head-to-head contact, and sharing clothing, bed linens, combs, brushes, and hats also can pass them along.

Pets can't catch head lice and pass them on to people or the other way around.

Do Kids Have to Stay Home From School?

In the past, kids with head lice were kept home from school. But now doctors don't recommend these "no-nit" policies. In most cases, a child who has lice should stay at school until the end of the day, go home and get treatment, and return to school the next day. While they are at school, kids should avoid head-to-head contact with other kids.

Can We Prevent Head Lice?

To get rid of head lice and their eggs, and to help prevent them from coming back:

  • Wash all bed linens and clothing recently worn by anyone in your home who has lice in very hot water (130°F [54.4°C]), then put them in the hot cycle of the dryer for at least 20 minutes.
  • Dry clean anything that can't be washed (like stuffed animals). Or put them in airtight bags for at least 3 days.
  • Vacuum carpets and any upholstered furniture (in your home or car), then throw away the vacuum cleaner bag.
  • Soak hair-care items like combs, barrettes, hair ties or bands, headbands, and brushes in rubbing alcohol or medicated shampoo for 1 hour. You also can wash them in hot water or throw them away. Tell kids not to share these items.
  • Because lice easily pass from person to person in the same house, bedmates and infested family members also need treatment to prevent the lice from coming back.
  • Tell kids to try to avoid head-to-head contact at school (in gym, on the playground, or during sports) and while playing at home with other children.
  • Every 3 or 4 days, check kids who had close contact with a person who has lice. Then, treat any who have lice or nits close to the scalp.

Will They Ever Be Gone?

As many parents know, fighting head lice can be an ongoing battle. There's no doubt that they can be hard bugs to get rid of.

If you've tried everything and your child still has lice, it could be because:

  • some nits were left behind
  • your child is still around someone who has lice
  • the treatment you're using isn't effective

If your child has lice 2 weeks after you started treatment or if your child's scalp looks infected, call your doctor.

Remind your child that while having lice can be embarrassing, anyone can get them. Having head lice is not a sign of dirtiness or poor hygiene. The pesky little bugs can be a problem no matter how often kids do — or don't — wash their hair or bathe.

As frustrating as head lice can be, there is light at the end of the tunnel. Be patient and follow the treatments and prevention tips from your doctor, and soon your family will be lice-free.

Date reviewed: June 2015