Lice

What are lice?

Lice are tiny wingless insects. They are less than 1/8 inch long (1 to 3 millimeters), or about the size of a sesame seed. There are several types of lice, including head lice, pubic lice, and body lice.

Lice feed on humans and animals, usually in the hairy parts of the body. They bite through the skin to suck blood. The bites can cause itching and sometimes skin irritation. Lice attach their eggs, called nits, to the hairs in the scalp, genital area, or other parts of the body. The nits hatch after several days, producing more lice. Lice are not dangerous and don’t spread disease.

How do people get lice?

You can get lice by coming into contact with living lice or their eggs. It may happen from sharing personal items such as combs, brushes, and hats. Sometimes it happens with close sexual contact with another person. Lice may live for a short time on clothing, bedding, and towels, but they cannot live long away from a warm human body.

What are the symptoms?

Sometimes lice don’t cause any symptoms. Most often, however, you have some itching. Your skin may become red and irritated, especially if you are scratching your skin. You may have small, red, itchy bumps.

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 will examine you and look for lice and nits.

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.

Use the anti-lice rinse or shampoo according to the instructions on the package or your healthcare provider's directions. Your provider will probably recommend that you repeat the treatment in 1 week because the nonprescription products kill only crawling lice. They don’t kill unhatched nits. So a second treatment in 7 to 10 days after the first may be needed to kill newly hatched lice.

If a nonprescription product does not kill the lice, you may need a shampoo prescribed by your healthcare provider. Prescription shampoos contain either malathion or lindane to kill the lice. These medicines may have side effects. It is usually better to try one of the safer, nonprescription products first.

• Malathion can sting if your skin 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 after you apply it. Don’t use a hair dryer to dry the hair during this time. Let the hair dry naturally.
• Lindane is rarely prescribed because it can cause seizures if it is not used correctly. Also, lindane is not as effective as it used to be because lice are getting resistant to it. Lindane should never be used by small children or women who are pregnant or breastfeeding. Carefully follow your healthcare provider’s directions for its use. Don’t overuse it.

If you are pregnant or breastfeeding, check with your healthcare provider before you use any type of anti-lice product.

If the lice are in your eyebrows or eyelashes, you will probably need to remove them carefully with your fingers. In some cases, your provider may prescribe medicine that is safe for the eyes.

After treatment with antilice medicine, the nits will still be on the hairs. You must remove all of the nits. Use a fine-tooth comb, tweezers, or your fingers to remove the nits.

Check everyone else living in your home and treat them if they have lice. Ask your healthcare provider to recommend the best treatment based on their ages and whether they are pregnant.

Treatment of your environment is as important as treatment of the hair and skin. You must get rid of all lice. Clean combs and brushes well by soaking them in a disinfectant such as Lysol. All clothing, bedding, and towels must be washed in hot water and dried in a hot dryer. Contaminated clothing that cannot be washed or dry cleaned should be sealed in a plastic bag for 2 weeks to make sure that you have killed all of the lice. (The lice can live for only a few days off the body.) Sometimes people are advised to buy a special lice insecticide spray to use on furniture. However, careful vacuuming may be as effective in most cases. Pets don’t need to be treated.

What can be done to help prevent lice?

The best way to prevent lice in the genital area is to have just one sexual partner who has no other partners, or to avoid intimate sexual contact. Condoms are not good protection against lice because they don’t cover the hairy areas where the lice live. You should also avoid contact with contaminated clothing, bed clothing, sleeping bags, and public toilet seats.

Prevention of head lice is more difficult, especially among children. Lice can move from person to person from close contact during play. They can get on hats, hooded coats, scarves, combs, brushes, pillows, and cuddly toys. To help prevent head lice, don’t share these items.

Body lice, which are different from head or pubic lice, are usually found only on people who don’t have access to changes of clothes or baths or whose mental health prevents them from practicing good hygiene. Anyone who bathes regularly and who regularly has access to freshly laundered clothing and bedding is not likely to have body lice.

Because it is so hard to prevent the spread of head lice among preschool and school-age children, head 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.