Lice (Overview of the Three Types)

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 in after several days, producing more lice. Lice are not dangerous, and do not 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 do not 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 or fingernails.

How is it diagnosed?

Your healthcare provider can tell if you have lice by examining you.

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 a nonprescription product does not kill the lice, your provider may prescribe a shampoo containing the medicine lindane. However, the nonprescription medicines are safer than lindane for preschool children. Lindane can cause seizures if it is not used correctly. Carefully follow the directions for its use, and do not overuse it. If you are pregnant, 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 dead nits will still be on the hairs. 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 signs of new lice. Use a fine-tooth comb, tweezers, or your fingers to remove the dead nits.

Check everyone else living in your home and treat them if they have lice. Also, treatment of your environment is as important as the treatment of the hair and skin. You must get rid of any remaining lice. Combs and brushes should be thoroughly cleaned, for example, by soaking in a disinfectant such as Lysol. All clothing, bedding, and towels must be laundered 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 nits. 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 do not 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 do not cover the hairy areas where the lice live. You should also avoid contact with contaminated clothing, bed clothing, and 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, do not share these items.

Body lice, which are different from head or pubic lice, are usually found only on people who do not 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.