The head louse is a tiny, wingless parasitic insect that lives among human hairs and feeds on tiny amounts of blood drawn from the scalp. Lice (the plural of louse) are a very common problem, especially for kids. They're contagious, annoying, and sometimes tough to get rid of.
But while they're frustrating to deal with, lice aren't dangerous. They don't spread disease, although their bites can make a child's scalp itchy and irritated, and scratching can lead to infection.
It's best to treat head lice quickly once they're found because they can spread easily from person to person.
Signs of Head Lice
Although they're very small, lice can be seen by the naked eye. 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 sort of like dandruff, only they can't be removed by brushing or shaking them off.
Unless the infestation is heavy, it's more common to see nits in a child's hair than it is to see live lice crawling on the scalp. Lice eggs hatch within 1 to 2 weeks after they're laid. After hatching, the remaining shell looks white or clear and stays firmly 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.
Adult lice and nymphs (baby lice). The adult louse is no bigger than a sesame seed and is grayish-white or tan. Nymphs are smaller and become adult lice about 1 to 2 weeks after they hatch. If head lice is not 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 actually due to a reaction to the saliva of lice. However, the itching may not always start right away — that 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 moving around on or tickling their heads.
Small red bumps or sores from scratching. For some kids, the irritation is mild; for others, a more bothersome rash may develop. Excessive scratching can lead to a bacterial infection (this can cause swollen lymph glands and red, tender skin that might have crusting and oozing). If your doctor thinks this is the case, he or she may treat the infection with an oral antibiotic.
You may be able to see the lice or nits by parting your child's hair into small sections and checking for lice and nits with a fine-tooth comb on the scalp, behind the ears, and around the nape of the neck (it's rare for them to be found on 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.
See your doctor if your child is constantly scratching his or her head or complains of an itchy scalp that won't go away. The doctor should be able to tell you if your child is infested with lice and needs to be treated. Not all kids have the classic symptoms of head lice and some can be symptom-free.
Also be sure to check with your child's school nurse or childcare center director to see if other kids have recently been treated for lice. If you discover that your child does, indeed, have lice or nits, contact the staff at the school and childcare center to let them know. Find out what their return policy is. Most usually allow kids to return after one topical treatment has been completed.
Are Lice Contagious?
Lice are highly contagious and can spread quickly from person to person, especially in group settings (like schools, childcare centers, slumber parties, sports activities, and camps).
Though they can't fly or jump, these tiny parasites have specially adapted claws that let them crawl and cling firmly to hair. They spread mainly through head-to-head contact, but sharing clothing, bed linens, combs, brushes, and hats also can pass them along. Kids are most prone to catching lice because they tend to have close physical contact with each other and share personal items.
And you may wonder if Fido or Fluffy may be catching the pests and passing them on to your family. But rest assured that pets can't catch head lice and pass them on to people or the other way around.
Your doctor can recommend a medicated shampoo, cream rinse, or lotion to kill the lice. These may be over-the-counter (OTC) or prescription medications, depending on what treatments have already been tried. Medicated lice treatments usually kill the lice and nits, but it may take a few days for the itching to stop. For very resistant lice, an oral medication (medicine taken by mouth) might be prescribed.
Make 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 only safe for kids 2 years and older. It's important to follow the directions exactly because these products are insecticides. Applying too much medication — or using it too often — can increase the risk of causing harm. Follow the directions on the product label.
Treatment may be unsuccessful if the medication is not used correctly or if the lice are resistant to it. After treatment, your doctor may suggest combing out the nits with a fine-tooth comb and also may recommend 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. You'll need to remove the nits and lice by hand.
To remove lice and nits by hand, use a fine-tooth comb on your child's wet, conditioned hair every 3 to 4 days for 3 weeks after the last live louse was seen. Wetting the hair beforehand is recommended because it temporarily immobilizes the lice 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. Good old-fashioned water works just fine.
Wet combing is also an alternative to pesticide treatments in older kids. Though petroleum jelly, mayonnaise, or olive oil are sometimes used in an attempt 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.
Make sure you 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.
Do Kids Have to Stay Home From School?
In the past, kids with head lice were kept home from school, but now doctors no longer 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.
Here are some simple ways to get rid of the lice and their eggs, and help prevent a lice reinfestation:
- Wash all bed linens and clothing that's been recently worn by anyone in your home who's infested in very hot water (130ºF [54.4ºC]), 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 just throw them away.
Because lice are easily passed from person to person in the same house, bedmates and infested family members also will need treatment to prevent the lice from coming back.
In your efforts to get rid of the bugs, there are some things you shouldn't do. Some don'ts of head lice treatment include:
- Don't use a hairdryer on your child's hair after applying any of the currently available scalp treatments because some contain flammable ingredients. A hair dryer could also cause live lice to blow into the air and spread 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, as these treatments can be harmful. Head lice don't survive long once 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 medication more than three times on one person. If it doesn't seem to be working, your doctor may recommend another medication.
- Don't use more than one head lice medication 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 lead to allergic reactions on the scalp and have not been approved by the U.S. Food and Drug Administration (FDA). Also, there are no studies to show whether or not such treatments actually work.
- Don't use chemicals such as gasoline or kerosene on the hair. These are highly flammable and should never be used to treat lice on anyone.
Tips to Remember
Having head lice is not a sign of dirtiness or poor hygiene. The pesky little bugs can be a problem for kids of all ages and socioeconomic levels, no matter how often they do — or don't — wash their hair or bathe. It also doesn't matter how long or short a person's hair is.
However, these tips can help to prevent kids from getting lice (or from becoming reinfested):
- 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.
- Tell kids not to share combs, brushes, hats, scarves, bandanas, ribbons, barrettes, hair ties or bands, towels, helmets, or other personal care items with anyone else, whether they may have lice or not.
- Tell kids not to lie on bedding, pillows, and carpets that have recently been used by someone with lice.
- Every 3 or 4 days, examine members of your household who have had close contact with a person who has lice. Then, treat any who are found to have lice or nits close to the scalp.
Will They Ever Be Gone?
As many parents know firsthand, lice infestation can be an ongoing battle, especially in group settings. There's no doubt that they can be hard bugs to get rid of.
If you've followed every recommendation and your child still has lice, it could be because:
- some nits were left behind
- your child is still being exposed to someone with lice
- the treatment you're using isn't effective
If your child still has lice 2 weeks after you started treatment or if your child's scalp looks infected, call your doctor.
No matter how long the problem lasts, be sure to remind your child that although having lice can certainly be very embarrassing, anyone can get them. It's important for kids to understand that they haven't done anything wrong and that having lice doesn't make them dirty. And reassure them that as frustrating as getting rid of the lice can be, there is light at the end of the tunnel.
Be patient and follow the treatments and prevention tips as directed by your doctor, and you'll be well on your way to keeping your family lice-free.
Reviewed by: Rupal Christine Gupta, MD
Date reviewed: April 2015