Head lice are tiny parasites that live on the human head. They live and thrive by sucking tiny amounts of blood from the scalp and reproduce by laying their eggs in the hair. Perhaps surprisingly, head lice don’t spread disease.
What do head lice (and their eggs) look like?
The adult head louse has six legs and is about the size of a sesame seed. Descriptions of their color vary, but generally they range from beige to gray and may become considerably darker when they feed.
Lice often appear to be the same color as the hair they’ve infested, making them hard to see with the naked eye. You can spot them most easily in the areas behind the ears and along the hairline on the back of the neck.
Female lice lay up to ten minuscule eggs a day. Lice eggs (called nits) are oval in shape. They may appear to be the color of their host’s hair, ranging from white to yellow to brown.
What’s the life cycle of a typical louse?
The female louse attaches her eggs to human hair shafts with a waterproof, glue-like substance. This ensures that the nits can’t be washed, brushed, or blown away, unlike dandruff and other bits of stuff in the hair that often gets mistaken for nits.
She lays her eggs a fraction of an inch from the scalp, where it’s nice and warm – just right for hatching. Nits typically hatch eight or nine days after they’re laid. Once the eggs have hatched, their yellow or white shells remain attached to the hair shaft, moving farther from the scalp as the hair grows. As a result, empty nit shells attached to hairs are usually found farther away from the scalp than live eggs are.
Baby lice, known as nymphs, are not much bigger than the nits and tend to be light in color. Nine to 12 days later, they become adults and mate, the females lay their eggs, and the cycle continues.
An adult louse can live up to 30 days on the human head.
How did my child get lice?
Your child probably picked up lice from an infested sibling or playmate. Lice are crawling insects. They can’t hop, jump, or fly, but they can crawl from one head to another when people put their heads together – for example, when they hug or lay their heads on the same pillow.
Once female lice find their way to a child’s head, they lay eggs and begin to populate the area. You can’t catch nits; they have to be laid by live lice.
Since lice can live for up to a day off of the human head, it’s theoretically possible to get infested if your hair makes contact with items such as hats, combs, or brushes if they were used recently by an infested person. However, this is less likely than human-to-human spread.
A healthy louse will rarely leave a healthy head (except to crawl onto another healthy head!), and lice found on combs are usually injured or dead.
Are lice more common in dirty conditions?
It’s a myth that lice are a product of poor hygiene or poverty. Head lice are equal-opportunity parasites. They like clean hair as well as dirty hair and can flourish in even the wealthiest communities.
So, when lice are going around, it’s no one child or family’s fault. If your child has lice, chances are they’re traveling through the neighborhood or school. And your child has probably unknowingly infected others.
Head lice are most common among preschool- and elementary school-age children and their families and caregivers. Some studies suggest that girls get head lice more often than boys. This may be because they have more head-to-head contact with each other and longer hair that provides more warmth and darkness (two things lice love).
Interestingly, lice are much less common among African Americans in the United States than among people of other races. This may be because lice claws have a tougher time grasping the shape and width of African American hair.
How to tell if you have lice?
When you became a parent, you probably never imagined yourself hunting for lice in your child’s hair. But that’s just what you (or someone) will have to do if you suspect that your child is infested.
When the bad news comes from a school
Many schools do regular lice checks during the school year, examining every child’s head. If they find lice, they’ll let you know. Be sure to do your own checking, though, to confirm their finding.
You may instead get a note warning that someone in your child’s class or school has lice. That’s your signal to check your own child’s head. It’s best to do this as soon as possible, because the sooner you find the lice, the easier they are to handle. And if you do find lice, you’ll need to check (and possibly treat) the whole family.
How to inspect your child’s head
The sesame-seed-size creatures and their teeny-tiny eggs are quite hard to spot. To find out whether you need to take action, try the following two- to three-step process.
If you can’t spot them via a visual inspection (step 2), try wet combing (step 3). A 2009 study in the Archives of Dermatology found that “wet-combing” accurately identified active head lice infestations in 90 percent of cases. In contrast, visual inspections accurately identified 29 percent.
You’ll need really good light and a pair of strong drugstore reading glasses or a magnifying glass (unless you have the eyes of an eagle). If you move on to step three, you’ll also need a metal lice comb and some hair conditioner.
Step 1: Look for the signs and symptoms of head lice
Your child may have one or more of these symptoms:
- A tickling feeling on the scalp
- A sensation that something is moving in the hair
- Itching caused by an allergic reaction to lice bites (kids may scratch or rub their scalp, especially around the back of the head or ears)
- Sores on the head caused by scratching
- Trouble sleeping (lice are more active in the dark)
Step 2: How to search for lice, stage one (dry hair)
- Check your child’s scalp.
Part the hair in various places and check the scalp behind the ears and at the nape of the neck. You may notice sores or a rash where your child has been scratching.
- Look for movement in the hair.
You’re not likely to see thelice themselves. They’re very small, move quickly, and avoid light, so they’re difficult to spot.
- Look for lice eggs, known as nits.
These tiny white or yellowish tear drop-shaped sacs are attached to the hair near the scalp (within a quarter inch if they haven’t yet hatched). Nits may be easier to feel than to see: They’ll feel like grains of sand.
- Make sure the “nits” you see are really nits.
Nits are often hard to distinguish from dandruff or flakes of hair products. The difference is that nits stick to the hair like glue while dandruff and other flakes are easily removed from the hair shaft.
- Make sure the nits you find are still alive.
If the only nits you find are more than a quarter inch from the scalp, they may have already hatched and your child may no longer be infested. (Nits can only hatch in the warmth right next to the scalp. After they hatch, the empty egg remains attached to the hair and grows farther and farther from the scalp.) Only viable nits – those very close to the scalp – or live lice are proof of a current infestation.
Step 3: How to search for lice, stage two (wet hair)
You’ll need to go on to this step if you can’t tell whether there’s an infestation by looking at your child’s hair and feeling it, the way you did in step 2. Studies have found that a lice comb is the best tool for finding live lice. (A flea comb may also work.) The teeth on a regular comb are too far apart to nab the tiny lice.
- Wet your child’s hair.
- Pour on lots of conditioner.
- Comb the hair out in sections, from the roots to the ends, with a lice comb.
- If there are lice in your child’s hair, you should see them on the comb.
(Shaking the comb out into a plastic bowl after every swipe can help you see them better.)
If you determine that your child does have lice, check the other kids and adults in your house. You’ll need to treat everyone to effectively rid your family of lice. If you follow these steps and you’re still not sure, have your child checked by a doctor or at a lice salon.
How to get rid of lice in your child’s hair
If your child has lice, you’ll need to take steps to get rid of them.
Lice are itchy and annoying and they won’t go away on their own. And your child can spread them to others – even to you – through close, usually head-to-head contact. That’s why parents often find themselves scratching too.
First, confirm that your child has lice
Before you go down this labor-intensive road, make sure your child has a confirmed case of head lice. That means you’ve spotted viable nits (lice eggs) or live lice in your child’s hair.
If you haven’t seen the signs yourself or feel uncertain about what you’re seeing, find out how to tell for sure whether your child has lice.
Then, choose a method for getting rid of lice
You’ll hear lots of conflicting recommendations for dealing with lice. Even official health sources such as government agencies and doctor associations differ. And friends, relatives, and online resources offer all sorts of home remedies and alternative medicines.
Consult your doctor or another health professional to make sure the method you choose is likely to be safe and effective.
Here are the options recommended by doctors, lice experts, and parents:
- Lice medicine and lice combing combined
Many parents try this approach: Apply drugstore lice medicine to the hair and follow up with frequent comb-outs using a high-quality metal lice comb.
- Over-the- counter lice-killing medicine alone
A 2010 American Academy of Pediatrics (AAP) report on head lice recommends using a drugstore pediculicide (lice-killing product). These are sold as a cream rinse, shampoo, gel, mousse, or other hair product. The AAP recommends applying as directed and then reapplying on day nine to catch any lice that may have hatched.
The report says that lice combs don’t help eradicate lice once you’ve applied the lice medicine, although they’re useful for diagnosing a case of head lice and for combing out lice and eggs killed by the pediculicide.
4.Lice comb alone
The National Pediculosis Association is one group that advocates combing lice and nits from the hair with a special lice comb instead of using a pediculicide. The group doesn’t rule out pediculicides completely but warns that these medicines are pesticides and potentially harmful to children. It states on its website, “The NPA believes that the mechanical method of removing head lice with a comb is the safest and most effective method.”
- Alternative methods
You’ll find all sorts of “natural” lice remedies at drugstores, natural food stores, and online. These products are not regulated by the FDA and there’s no scientific proof that they’re safe or effective (and some could be toxic, so be careful). Home remedies ranging from olive oil, baby oil, mayonnaise, and petroleum jelly to using a blow dryer are also popular, but not scientifically tested.
If you need help or have more questions call us at:
Health and Wellness Associates
Chicago Childrens Hospital