Mention the words 'head lice" and people will begin backing away immediately. Although head lice are common and easily treatable, they can spread through a family or through a classroom if not treated quickly. Here's what to look for and how to treat head lice.

Head lice are tiny insects that can live in human hair. About the size of a sesame seed, a louse has six legs and ranges in color from light beige to black. Lice live in hairy areas of the body and feed by biting and sucking blood.

Lice lay their eggs, called nits, in the hairs near the scalp, especially the hairline area at the back of the neck and behind the ears. These small, silvery, oval eggs hatch within 7–10 days. Only nits within a quarter-inch of the scalp are considered live and active. Lice crawl slowly, up to 12 inches per minute, and do not jump, hop, or fly. You can’t catch head lice from or give it to pets. Head lice affect only humans.

The most common symptom of head lice is itching. Children often come home from school or day care with head lice. It can then spread to the whole family, either by direct contact with the child’s head or contact with clothing or other accessories that person uses (like a brush or hair band).

Nits are much easier to find than lice but are difficult to remove. Both nits and lice must be hand-picked or taken out with a nit-comb (found in pharmacies). Dandruff, lint, and hairspray residue can be mistaken for nits, but these can easily be brushed from hair.

Shampoos and cream rinses are available to treat head lice. Some can be purchased over the counter, while others need a prescription. Ask your doctor or public health clinic what you should use.

Lice shampoos can be toxic to the brain and parts of the nervous system if misused, overused or accidentally swallowed. Check with your child’s doctor:

• Before using lice shampoos on infants younger than 6 months old
• If your child needs more than two treatments

When you use a lice treatment shampoo or rinse, follow the instructions on the bottle exactly. More is not better. Too much can irritate skin and be absorbed through the skin into the bloodstream, causing unwanted side effects. Use the medicine only on the hair and scalp. If you use the shampoo on your child’s hair during a bath, rinse their body quickly.

Protect your child’s eyes and wear rubber gloves when applying the shampoo. After the first treatment, comb or pick out the nits while the hair is still slightly damp. You only need to remove the nits closest to the scalp. One treatment is usually enough to kill the lice but not the nits. A second treatment is often needed 7–10 days later.

Lice can live for 24 hours in clothing or items that have touched hair, including bed linens, coats, hats, upholstered furniture, combs, and brushes. Nits and immature lice can even live longer. It’s important to do the following steps to keep the lice from coming back:

• Treat family members’ hair with lice shampoo if you find lice in it. Check everyone else in the household every 2–3 days for crawling lice or nits.
• Wash clothing and bed linens in hot water in a washing machine. This should kill the lice and eggs. If you can’t wash something, have it dry cleaned or put it in a hot dryer for 20 minutes.
• Vacuum your upholstered furniture and carpet. Spraying is not recommended because the vapors are too poisonous for humans and animals.
• Soak combs, brushes, and hair accessories in lice-killing products for one hour. You can also put them in boiling water for 10 minutes.

Items that can’t be washed or vacuumed, such as stuffed animals, can be placed in a tightly closed plastic bag for two weeks. Lice and eggs must have human contact to live any longer. At the end of 14 days, you can remove the item from the bag without any risk of getting head lice.

Teach your children not to share combs, brushes, hats, and coats. Use blow dryers to dry their hair. Check their hair if they complain about itching, and get rid of lice as soon as you find them. This can prevent them from spreading in your home.

Make sure everyone who comes in contact with a child with head lice is checked. They should only be treated if lice are found in their hair. Call your healthcare provider if head lice continues to be a problem in your home.

If you have more questions or can’t get rid of lice, call your doctor or medical advisor, the school nurse, or the local public health department.