The bane of many parents, the head louse is a tiny, wingless parasitic insect that lives among human hairs and feeds on extremely small amounts of blood drawn from the scalp. Although they may sound gross, lice (the plural of louse) are a very common problem, especially for kids ages 3 years to 12 years (girls more often than boys).

Lice aren't dangerous and they don't spread disease, but they are contagious and can just be downright annoying. Their bites may cause a child's scalp to become itchy and inflamed, and persistent scratching may lead to skin irritation and even infection.

It's wise to treat head lice quickly once the diagnosis is made because they can spread easily from person to person.

Signs of Head Lice

Though very small, lice can be seen by the naked eye. What you or your doctor might see by thoroughly examining your child's head:

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 continues to be firmly attached to the hair shaft. This is the stage when it's easiest to spot them, as the hair is growing longer and the egg shell is moving further 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. Most lice feed on blood several times a day, but 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 your 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 (the skin would become red and tender and may have crusting and oozing along with swollen lymph glands). 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're able to move fast.

Call 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 may be totally 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 (schools, childcare centers, slumber parties, sports activities, and camps).

Though they can't fly or jump, these tiny parasites have specially adapted claws that allow them to crawl and cling firmly to hair. They spread mainly through head-to-head contact, but sharing clothing, bed linens, combs, brushes, and hats can also help pass them along. Kids are most prone to catching lice because they tend to have close physical contact with each other and often 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.

Treatment

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 might be prescribed.

It's important to follow the directions exactly because these products are insecticides. Applying too much medication — or using it too frequently — can increase the risk of causing harm. Follow the directions on the product label to ensure that the treatment works properly.

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 years 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 2 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.

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 have not been proven to be effective.

Keep in mind that head lice don't survive long once they fall off a person. So it's unnecessary to spend a great deal of time and money trying to rid the house of lice.

Preventing Reinfestation

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 (130° F [54.4° C]), then put them in the hot cycle of the dryer for at least 20 minutes.
• Have bed linens, clothing, and stuffed animals and plush toys that can't be washed dry-cleaned. Or, put them in airtight bags for 2 weeks.
• Vacuum carpets and any upholstered furniture (in your home or car).
• Soak hair-care items like combs, barrettes, hair ties or bands, headbands, and brushes in rubbing alcohol or medicated shampoo for 1 hour. You can also 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 will also need treatment to prevent the lice from coming back.

Dont's

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 hair dryer on your child's hair after applying any of the currently available scalp treatments because some contain flammable ingredients.
• Don't use a cream rinse 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 they can be harmful.
• 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.

Preventing Lice

Having head lice is not a sign of uncleanliness 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 — clean their hair or bathe.

However, you can help to prevent kids from getting lice — or from becoming reinfested with lice — by taking the following precautions:

• 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 those 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 a persistent nuisance, especially in group settings. If your child still has lice and you've followed every recommendation, 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

There's no doubt that they can be hard bugs to get rid of. 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 emphasize to 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 aggravating as getting rid of the annoying insects 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 for keeping the bugs at bay, and you'll be well on your way to keeping your family lice-free.

Reviewed by: Yamini Durani, MD
Date reviewed: May 2011