Diagnosis

During an examination, your doctor may look for lice using a magnifying lens and check for nits using a special light, called a Wood's light, which makes the nits look pale blue.

Head lice

A diagnosis of head lice can be made after a live young or adult louse in the hair or on the scalp is found, or after one or more nits is seen on hair shafts located within 1/4 inch (6.4 millimeters) of the scalp.

If you don't see any live lice or you see nits that are more than 1/4 inch away from the scalp, the infestation is probably no longer active. Nits should be removed to prevent a recurrence.

Body lice

A diagnosis of body lice may be made if eggs or crawling lice are found in the seams of clothing or on bedding. It's possible to see a body louse on skin if it crawls there to feed.

Pubic lice

Pubic lice are diagnosed when moving lice or nits are seen on hair in the pubic area or on other areas of coarse hair, such as chest hair, eyebrows or eyelashes.

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, others) or permethrin (Nix) are usually the first option used to combat lice infestations. These work best if you follow the directions very closely.

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

  • Oral prescription medication. Although it was originally developed for treating worm diseases, oral ivermectin 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 (Ovide) is a prescription medication that you apply to your hair and then rub into your hair and scalp. Malathion 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 (Ulesfia) 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.

    Finally, lindane is a prescription shampoo that's sometimes prescribed when other measures fail. However, due to increasing resistance of lice to this medication and to serious neurological side effects, lindane is no longer recommended as a first line treatment for head lice.

Body lice

If you have body lice, you don't need treatment. However, you must take the same self-care measures, such as treating clothing and other items, as you would for head lice. If self-care measures fail to get rid of the lice, your doctor might recommend trying one of the nonprescription or prescription treatments 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.

Lifestyle and home remedies

You can get rid of lice with a patient, thorough approach that involves cleaning yourself or your child and any personal belongings that may be contaminated.

These steps may help you eliminate lice infestations:

  • Check other household members for lice and nits. Treat anyone who has signs of an infestation.
  • Use lotions and shampoos. Choose from among several over-the-counter lotions and shampoos (Nix, Rid, others) designed to kill lice. Apply the product according to package instructions.

    You may need to repeat treatment with the lotion or shampoo in about nine days. These lotions and shampoos typically aren't recommended for children under age 2.

  • Comb wet hair. Use a fine-toothed or nit comb to physically remove the lice from wet hair. Repeat every three to four days for at least two weeks. This method may be used in combination with other treatments and is usually recommended as the first line treatment for children under age 2.
  • Wash contaminated items. Wash bedding, stuffed animals, clothing and hats with hot, soapy water — at least 130 F (54 C) — and dry them at high heat for at least 20 minutes.
  • Seal unwashable items. Place them in an airtight bag for two weeks.
  • Vacuum. Give the floor and furniture a good vacuuming.
  • Wash combs and brushes. Use very hot, soapy water — at least 130 F (54 C) — or soak combs and brushes in rubbing alcohol for an hour.

One thing you don't need to worry about is your household pets. Lice prefer people to pets, so your pets don't need any treatment for lice.

Alternative medicine

A number of home or natural remedies, such as mayonnaise or olive oil, are used to treat head lice infestations, but there's little to no evidence of their effectiveness.

For parents looking at alternative treatment methods, at least two have weak evidence supporting their use. However, more research is needed. For the first, you apply the over-the-counter cleanser Cetaphil to the hair and scalp, dry it with a hair dryer, and then leave it overnight and wash it out in the morning. Repeat this treatment once a week for three weeks.

The other is a special machine that uses hot air to dehydrate head lice and their eggs. The machine requires special training and is currently available only at professional lice treatment centers.

A regular hair dryer can't be used to do this at home as it's too hot and could burn the scalp. The machine at the clinics uses air that is cooler than most hair dryers but at a much higher flow rate to kill the lice by drying them out.

Preparing for your appointment

Often, you can get rid of lice with over-the-counter treatments and by properly washing contaminated household items, such as sheets, towels and clothes. If these measures don't work, see your primary care medical provider.

Here's some information to help you get ready for your appointment, and know what to expect from your doctor.

What you can do

  • Write down any symptoms you're experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment.
  • Write down key personal information, including when you might have been exposed to lice, whom you might have exposed and what household items might be contaminated.
  • Make a list of all medications, vitamins or supplements that you're taking.
  • Write down questions to ask your doctor. Your time with your doctor is limited, so preparing a list of questions ahead of time will help you make the most of your time together. List your questions from most important to least important in case time runs out.

Some basic questions to ask your doctor about lice include:

  • How do I treat lice?
  • Is there a generic alternative to the medicine you're prescribing?
  • How often can I safely use this product?
  • How do I get rid of lice from household items?
  • Who do I need to inform about my condition?
  • What other measures do I need to take to avoid re-infesting myself or others?
  • Are there any brochures or other printed material that I can take home with me? What websites do you recommend?
  • Should I plan for a follow-up visit?

In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment when you don't understand something.

What to expect from your doctor

Your doctor is likely to ask you a number of questions, such as:

  • When did you first begin experiencing symptoms?
  • How were you exposed to lice?
  • Is there anyone you might have exposed to lice?
  • How severe are your symptoms?

What you can do in the meantime

If you think or know you have lice, avoid sharing personal items, bedding, towels or clothing. Bathe and follow self-care measures, including washing contaminated items in hot water.

If you think or know you have a pubic lice infestation, also avoid sexual activity until you've been treated.

May 19, 2018
References
  1. Devore CD, et al. Head lice. Pediatrics. 2015;135:e1355.
  2. AskMayoExpert. Lice. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2018.
  3. Bennett JE, et al., eds. Lice (Pediculosis). In: Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 8th ed. Philadelphia, Pa.: Saunders Elsevier; 2015. https://www.clinicalkey.com. Accessed March 30, 2018.
  4. Goldstein AO, et al. Pediculosis capitis. https://www.uptodate.com/contents/search. Accessed March 31, 2018.
  5. Head lice: Treatment. Centers for Disease Control and Prevention. https://www.cdc.gov/parasites/lice/head/gen_info/faqs_treat.html. Accessed March 30, 2018.