Head Lice

What are head lice?

Head lice are tiny wingless insects. They are less than 1/8 inch long (2 to 3 millimeters).

Head lice live in the hair and bite the scalp to suck blood. They attach their eggs, called nits, to the hair. The eggs then hatch in 8 to 10 days, producing more lice.

It is very common for schoolchildren to have head lice.

How do people get head lice?

You can get lice by coming into contact with living lice or their eggs. For example, sharing personal items such as a comb or hat is a way you can get lice. Lice may crawl or fall onto clothing, bedding, towels, or furniture, as well as combs and brushes. Head lice can live up to 3 days on such items.

What are the symptoms?

Itching is the most common symptom. Often, however, there are no symptoms, especially at first, when there are just a few lice and nits.

Sometimes you may see the lice or nits. The nits look like tiny white dots attached firmly to a hair. They look like dandruff. Dandruff, however, is easily brushed out of the hair. Nits cannot be brushed or flicked off. They must be pulled off the hair with your fingers.

How is it diagnosed?

Your healthcare provider looks for lice or nits in your hair.

How is it treated?

Lice will not go away without proper treatment. Nonprescription anti-lice products, such as Nix rinse or RID shampoo, can be used to kill lice and nits.

Use the anti-lice rinse or shampoo according to the instructions on the package or your provider's directions. Your provider will probably recommend that you repeat the treatment in 1 week.

If nonprescription products do not kill the lice, your provider may prescribe a shampoo. Prescription shampoos contain either malathion or lindane to kill the lice. These medicines can have side effects.

• Malathion can sting if the scalp is irritated from scratching. It is also flammable, so it is very important to stay away from heat sources or flames for the 8 to 12 hours that the malathion is on the hair. Do not use a hair dryer to dry the hair during this time. Let the hair dry naturally.
• Lindane can cause seizures if it is not used correctly. Lindane also does not work as well as it did in the past because lice are becoming resistant to it. Carefully follow the directions for its use, and do not overuse it.

Because malathion has fewer side effects than lindane, it is often used first. If malathion does not kill the head lice, you may need to use lindane shampoo. The nonprescription products are safer than malathion or lindane for preschool children. If you are pregnant, check with your healthcare provider before you use any type of anti-lice product.

After the anti-lice treatment the dead nits will still be on your hair. You must remove all of them. Otherwise, if you see nits several days after your treatment, you will not know if they are old dead nits or a new infestation. You can remove the dead nits with a fine-tooth comb, tweezers, or your fingers.

Clean all items that have come into contact with the head and hair. Combs and brushes should be thoroughly cleaned, for example, by soaking in a disinfectant such as Lysol. Hats, scarves, towels, and bed sheets should be washed in hot water and dried in a hot drier. Contaminated clothing that cannot be washed or dry cleaned should be sealed in a plastic bag for 2 weeks to ensure death of nits. Vacuum the furniture.

What can be done to help prevent lice?

To help prevent lice, do not share personal items such as combs, brushes, hats, scarves, and towels.

Lice can be very hard to prevent among small children who nap together and share hats and cuddly toys. Because it is so difficult to prevent the spread of lice among preschool and school-age children, lice should not be seen as a sign of poor hygiene or failure by parents. The problem should just be dealt with in a calm, practical manner.