Treatment

Use medications that treat lice only as directed. Applying too much can cause red, irritated skin.

Head lice

Treatment for head lice may involve:

• Over-the-counter products. Shampoos containing pyrethrin (Rid, A200 Lice Treatment) or permethrin (Nix) are usually the first option used to combat lice infestations. Follow the directions closely when using these products.

  In some geographical locations, lice have grown resistant to the ingredients in over-the-counter treatments. If over-the-counter preparations don't work, your doctor can prescribe shampoos or lotions that contain different ingredients.

• Oral prescription medication. Oral ivermectin (Stromectol) effectively treats lice with two doses, eight days apart. This drug is typically used to treat infestations that haven't responded to other treatments.

  Children must weigh at least 33 pounds (15 kilograms) to take oral ivermectin. Side effects may include nausea and vomiting.

• Topical prescription medications. Malathion is a prescription medication that you apply to your hair and then rub into your hair and scalp. Malathion has a high alcohol content and is flammable, so keep it away from heat sources such as hair dryers, electric curlers and cigarettes.

  If you're pregnant or breast-feeding, talk to your doctor before using malathion. The drug isn't recommended for children 2 and under, and it's not clear if it's safe for use in 2- to 6-year-olds.

  Benzyl alcohol lotion is a prescription treatment that you apply to the scalp and hair for 10 minutes and then rinse off with water. Seven days later you repeat the treatment.

  Possible side effects include irritation of the skin, scalp and eyes as well as numbness at the application site. This medication isn't recommended for children younger than 6 months of age.

  Ivermectin lotion (Sklice) is a topical, single-dose treatment for head lice. You apply the lotion directly to dry hair and the scalp for 10 minutes and then rinse with water. Do not repeat this treatment without talking to your doctor first.

  Possible side effects include eye irritation or redness, dandruff, dry skin, and a burning sensation at the application site. This medication isn't recommended for children younger than 6 months of age.

  Spinosad topical suspension (Natroba) is a newer prescription treatment for head lice. You apply the medication to dry hair and the scalp for 10 minutes and then rinse with water. Repeat the treatment after seven days only if live lice are still present.

  Possible side effects include redness or irritation of the eyes and skin. This medication isn't recommended for children younger than age 4.

Body lice

If you have body lice, you must bathe with soap and water. After bathing, apply permethrin (Nix) to the affected areas before bedtime and then shower in the morning. You will need to repeat this treatment nine days after the first application.

You should also take the same self-care measures, such as treating clothing and other items, as you would for head lice.

Pubic lice

Pubic lice can be treated with many of the same nonprescription and prescription treatments used for head lice. Carefully follow the package instructions. Talk to your doctor about treatment of lice and nits on eyebrows or eyelashes.

Self-care

Whether you use over-the-counter or prescription shampoo to kill lice, much of the treatment involves self-care steps you can take at home. These include making sure all the nits are removed and that all clothing, bedding, personal items and furniture are decontaminated.

In most cases, killing lice that are on you isn't difficult. The challenge is getting rid of all the nits and avoiding contact with other lice at home or school.