What's a Louse?

A louse is a parasite (say: PAR-uh-site), which means it feeds off of other living things. Lice (the word for more than one louse) are about the size of a sesame seed, and are tan to gray in color. Lice need to suck a tiny bit of blood to survive, and they sometimes live on people's heads and lay eggs in the hair, on the back of the neck, or behind the ears.

It's very easy for a person with lice to give it to another person when they come into close head-to-head contact with each other. Sometimes, lice can be transmitted by friends sharing things that have touched the hair, such as combs, brushes, hats, and headphones. Lice cannot jump or fly, so a person can't catch lice by simply sitting near someone who has lice.

What a Bite Looks and Feels Like

If a person gets lice, it doesn't feel like anything at first. A louse lays tiny, oval eggs called nits. They are yellow, tan, or brown before the lice hatch. After the lice hatch, nits appear clear or white. They look a little like dandruff flakes but they can't be shaken off.

The lice mature within 1 to 2 weeks and begin feeding and attaching their tiny claws to the hair shaft. Louse bites look like tiny red spots on the skin, and they are very itchy.

What You Should Do

If your head is very itchy, tell an adult immediately. Getting lice has nothing to do with being dirty, and it's very common among kids who are in school together. It is something that will need to be cleared up as soon as possible.

What a Doctor Will Do

Doctors treat people who have lice by giving them a prescription for a medicated shampoo, cream, or lotion that kills lice, or instructing that they buy one off of the store shelf.

An adult will need to use a fine-tooth comb to get rid of the existing nits and follow the instructions for putting the medication in your hair to kill the lice. It's not a good a idea to use a hairdryer to dry a person's hair after using the medication, as some medicines contain flammable ingredients (which means they can catch on fire and burn easily).

It may take a few days for the itching to stop and the treatment may need to be repeated in 7 to 10 days to make sure any surviving lice are killed before they produce new eggs.

All the carpets and furniture in the house should be vacuumed, and bedding, clothing, and stuffed animals should be washed in hot water or placed in airtight bags for at least 10 days to kill the lice and eggs. Brushes, combs, and hair accessories should be soaked in hot water, washed with medicated shampoo, or thrown away.

How to Avoid Getting Bitten

It can be hard to avoid lice completely, but there are things you can do to protect yourself:

• If you know kids with lice, avoid touching them — especially their hair.
• Always bring your own pillows, sleeping bags, or sheets to a sleepover.
• Finally, do not share brushes, combs, hats, headphones, or hair accessories — like barrettes and headbands, with anyone else.

Reviewed by: Elana Pearl Ben-Joseph, MD
Date reviewed: April 2013