Head lice are tiny wingless insects. They live among human hairs and feed on blood
from the scalp.
Head lice are a common problem, especially for little kids. But teens can get them
too. They spread easily from person to person, and sometimes are tough to get rid
of. Their bites can make the scalp itchy and irritated, and scratching can lead to
Head lice are annoying, but they're not dangerous and they don't spread disease.
They're not a sign of poor hygiene — head lice need blood and they don't care
whether it's from someone who's clean or dirty.
It's best to treat head lice right away to prevent them from spreading.
What Are the Signs & Symptoms of Head Lice?
Lice are tiny, but you can still see them — though it's not always easy.
An adult louse is grayish white or tan and about the size of a small sesame seed.
Lice move fast, so you're actually more likely to see their eggs than the lice themselves.
Louse eggs are called nits. Nits look sort of like dandruff, except
they don't brush or fall off as easily as dandruff. Lice attach their nits to pieces
of hair, close to the scalp. If you think you have lice and see a small, oval blob
on a strand of hair, it's probably a nit.
If nits are yellow, tan, or brown, it means the lice haven't hatched yet. If the
nits are white or clear, the lice have hatched and just the egg remains. Lice eggs
hatch within 1 to 2 weeks after they're laid.
Besides seeing nits or lice on the head, itching — or the feeling of something
moving around on the scalp — is another clue that you might have lice. Like
mosquito bites, the itching is a reaction to the saliva of the insect. Some people
with lice also get a rash of small red bumps from scratching.
How Are Head Lice Treated?
The two main ways to treat lice are:
removing by hand
Medicine. If you think you have lice, call your doctor. Your doctor
can recommend a medicated shampoo, cream rinse, or lotion to kill the lice. These
may be over-the-counter (OTC) or prescription treatments. It all depends on what your
doctor thinks will work best for you.
Lice can be hard to get rid of. If you still have lice 2 weeks after you started
treatment, let your doctor know. Your doctor may want to try a different medication
or repeat treatment in case any nits were left behind and hatched after treatment.
Lice are insects, so the treatments for lice are basically insecticides or pesticides.
To avoid getting overexposed, you'll need to follow the directions carefully when
it comes to how much to use and how often to use it. Medicated lice treatments usually
kill the lice, but it may take a few days for the itching to stop.
Removing by hand. Your doctor may recommend wet combing in addition
to (or as an alternative to) chemical treatments. Medicated treatments aren't 100%
effective, so removing by hand is also important.
To remove lice and nits by hand, use a fine-tooth comb on wet, conditioned hair
every 3–4 days for 3 weeks after the last live louse was seen. Go through small
sections of hair at a time. Wetting the hair temporarily stops the lice from moving,
and the conditioner makes it easier to get a comb through the hair. When possible,
it works best to have someone else do the combing and removal.
You may have heard that petroleum jelly, mayonnaise, or olive oil can suffocate
head lice, but these treatments may not be effective.
If you choose to get rid of lice without using medicine, you'll need to remove
lice and nits carefully each week, for at least 3 weeks in a row. Watch for any live
lice and take action if you see them.
Scratching a lot can lead to a scalp infection. Call your doctor
as soon as possible if:
Your doctor may want to treat an infection with antibiotics.
A few important things to NOT do: Don't use a hairdryer after
applying scalp treatments. Some treatments for lice use flammable ingredients and
can catch on fire. Don't use pesticide sprays or hire a pest control
company to try to get rid of the lice; these can be harmful. Don't use
essential oils (such as ylang ylang oil or tea tree oil) to treat lice on the scalp.
They can cause allergic skin reactions and aren't approved by the U.S. Food and Drug
Administration (FDA). Don't ever use highly flammable chemicals such
as gasoline or kerosene.
How Can I Prevent Head Lice?
Lice can be tricky to get rid of because nits can remain unhatched on your head
or you might pick up lice that are still on bedding or other items. Here's what to
do if you've had lice — or someone in your family has:
Wash bed linens and clothing that anyone with lice has used recently. Use very
hot water (130°F [54.4°C]), then use the hot cycle of the dryer for at least
Take items that can't be washed to the dry cleaner. Or put them in airtight bags
for 2 weeks.
Vacuum carpets and any upholstered furniture, as well as car seats, then throw
away the vacuum cleaner bag.
Soak hair-care items like combs, barrettes, hair ties or bands, headbands, and
brushes in hot water or just throw them away.
Because lice can move easily from person to person in the same house, family members
should be checked for lice. Anyone who has them needs treatment.
Here are some ways to avoid getting lice in the first place:
Try to avoid head-to-head contact, like in gym or during sports.
Don't share combs, brushes, hats, scarves, bandanas, ribbons, barrettes, hair
ties or bands, towels, helmets, or other personal care items with anyone else.
Don't lie on bedding, pillows, and carpets that someone with lice has used in
the past couple of days.
If someone in your family or at school has lice, ask a parent or adult to check
your hair and scalp every 3–4 days to be sure you haven't picked up lice.