CDC - Lice - Head Lice - General Information - Treatment FAQs (2024)

On This Page

  • Is mayonnaise effective for treating head lice?
  • If the treatment for head lice doesn’t seem to be work, does this mean the lice are resistant and I need a different treatment?
  • Is there a treatment recommendation for certain age groups?
  • Are there any side effects from using these chemical treatments for head lice?
  • Is it necessary to remove all the nits?
  • Where can I go to have the nits removed from hair?
  • Why do some experts recommend bagging items for 2 weeks?
  • Should my pets be treated for head lice?
  • Should household sprays be used to kill adult lice?
  • Do I need to have my home fumigated?
  • Should I have a pest control company spray my house?
  • Will laundering kill head lice?
  • Which medicine is best?

Is mayonnaise effective for treating head lice?

CDC does not have clear scientific evidence to determine if suffocation of head lice with mayonnaise, olive oil, margarine, butter, or similar substances is an effective form of treatment.

If the treatment for head lice doesn’t seem to be working, does this mean the lice are resistant and I need a different treatment?

The following are several common reasons why treatment for head lice may fail sometimes:

  1. Misdiagnosis. The symptoms are not caused by an active head lice infestation.
  2. Applying the treatment to hair that has been washed with conditioning shampoo or rinsed with hair conditioner. Conditioners can act as a barrier that keeps the head lice medicine from adhering to the hair shafts; this can reduce the effectiveness of the treatment.
  3. Not following carefully the instructions for the treatment that is used. Some examples of this include not applying a second treatment if instructed to do so, or retreating too soon after the first treatment before all the nits are hatched and the newly hatched head lice can be killed. Another reason is retreating too late after new eggs have already been deposited.
  4. Resistance of the head lice to the treatment used. The head lice may have become resistant to the treatment. If the treatment used does not kill the head lice, your health care provider and pharmacist can help you be sure the treatment was used correctly and may recommend a completely different product if they think the head lice are resistant to the first treatment.
  5. Reinfestation. The person was treated successfully and the lice were eliminated, but then the person becomes infested again by lice spread from another infested person. Sometimes reshampooing the hair too soon (less than 2 days) after correctly applying and removing permethin can reduce or eliminate any residual (continued) killing effect on the lice.

Back To Top

Is there a treatment recommendation for certain age groups?

Before treating young children, please consult the child’s doctor, or the health department for the recommended treatment based on the child’s age and weight.

Are there any side effects from using these chemical treatments for head lice?

Treatments for head lice are generally safe and effective when used correctly. Some treatments may cause an itching or a mild burning sensation caused by inflammation of the skin on the scalp. Most products used to treat head lice are pesticides that can be absorbed through the skin. Therefore, all medicines used for the treatment of lice should be used with care and only as directed.

Is it necessary to remove all the nits?

No. The two treatments 9 days apart are designed to eliminate all live lice, and any lice that may hatch from eggs that were laid after the first treatment.

Many nits are more than ¼ inch from the scalp. Such nits are usually not viable and very unlikely to hatch to become crawling lice, or may in fact be empty shells, also known as casings. Nits are cemented to hair shafts and are very unlikely to be transferred successfully to other people.

However, parents may choose to remove all nits found on hair for aesthetic reasons or to reduce the chance of unnecessary retreatment.

More on: Head Lice Treatment

Back To Top

Where can I go to have the nits removed from hair?

CDC does not make recommendations about businesses that may offer such services. Your health care provider or local health department may be able to provide additional guidance. Removal of all nits after successful treatment with a pediculicide is not necessary to prevent further spread of head lice. Removal of nits after treatment with a pediculicide may be done for aesthetic reasons, or to reduce diagnostic confusion and the chance of unnecessary retreatment. Because pediculicides are not 100% ovicidal (i.e. do not kill all the egg stages), some experts recommend the manual removal of nits that are attached less than1 cm of the base of the hair shaft.

Why do some experts recommend bagging items for 2 weeks?

Head lice survive less than one or two days if they fall off the scalp and cannot feed. Head lice eggs (nits) cannot hatch and usually die within a week if they do not remain under ideal conditions of heat and humidity similar to those found close to the human scalp. Therefore, because a nit must incubate under conditions equivalent to those found near the human scalp, it is very unlikely to hatch away from the head. In addition, if the egg were to hatch, the newly emerged nymph would die within several hours if it did not feed on human blood.

However, although rarely necessary, some experts recommend that items that may be contaminated by an infested person and that cannot be laundered or dry-cleaned should be sealed in plastic bag and stored for 2 weeks to kill any lice that already are present or that might hatch from any nits that may be present on the items.

Should my pets be treated for head lice?

No. Head lice do not live on pets. Pets do not play a role in the spread of head lice.

Back To Top

Should household sprays be used to kill adult lice?

No. Using fumigant sprays or fogs is NOT recommended. Fumigant sprays and fogs can be toxic if inhaled or absorbed through the skin and they are not necessary to control head lice.

Do I need to have my home fumigated?

No. Use of insecticide sprays or fogs is NOT recommended. Fumigant spray and fogs can be toxic if inhaled or absorbed through the skin and they are not necessary to control head lice.

Routine house cleaning, including vacuuming of carpeting, rugs, furniture, car seats, and other fabric covered items, as well as laundering of linens and clothing worn or used by the infested person is sufficient. Only items that have been in contact with the head of the infested person in the 48 hours before treatment need be considered for cleaning.

Should I have a pest control company spray my house?

No. Use of insecticide sprays or fogs is NOT recommended. Fumigant spray and fogs can be toxic if inhaled or absorbed through the skin and they are not necessary to control head lice.

Routine vacuuming of floors and furniture is sufficient to remove lice or nits that may have fallen off the head of an infested person.

Will laundering kill head lice?

Washing, soaking, or drying items at a temperature greater than 130°F can kill both head lice and nits. Dry cleaning also kills head lice and nits. Only items that have been in contact with the head of the infested person in the 48 hours before treatment should be considered for cleaning.

Although freezing temperatures can kill head lice and nits, several days may be necessary depending on temperature and humidity; freezing is rarely (if ever) needed as a means for treating head lice.

Which medicine is best?

If you aren’t sure which medicine to use or how to use a particular medicine, always ask your physician, pharmacist, or other health care provider. CDC does not make recommendations about specific products. When using a medicine, always carefully follow the instructions contained in the package or written on the label, unless the physician and pharmacist direct otherwise.

Back To Top

CDC - Lice - Head Lice - General Information - Treatment FAQs (2024)

FAQs

What are the CDC guidelines for lice treatment? ›

General Guidelines

All infested persons (household members and close contacts) and their bedmates should be treated at the same time. Some pediculicides (medicines that kill lice) have an ovicidal effect (kill eggs). For pediculicides that are only weakly ovicidal or not ovicidal, routine retreatment is recommended.

When can you be around people after lice treatment? ›

After the first treatment, when the egg-laying lice are eliminated, you are no longer contagious. To stop the cycle of lice you must stop the egg laying first, then remove the nits. Timing is everything and you must complete the 3 well-timed treatments to ensure you are lice-free.

Why can't you use conditioner after lice treatment? ›

Do not use a conditioner. It can keep the lice medicine from working. Rinse well with warm water and towel dry. Do not use the towel again until it has been laundered.

How long should you quarantine after getting lice? ›

In the past, kids with head lice were kept home from school. But now doctors don't recommend these "no-nit" policies. In most cases, a child who has lice should stay at school until the end of the day, go home and get treatment, and return to school the next day.

Do you need to treat the whole family for head lice? ›

You can treat head lice without seeing a GP. You should check everyone in the house and start treating anyone who has head lice on the same day. There's no need to keep your child off school if they have head lice.

Do you have to treat everyone for lice? ›

Check other kids and adults in your household for head lice. Often, by the time you get a call from a school nurse, your child has had head lice for a while. Your whole family may need to be treated to prevent reinfestation.

What are the isolation precautions for lice? ›

Don't share personal items such as clothing, hats, combs, or hair accessories. Machine wash all of your personal items and clothing in hot water and place them in a hot dryer for at least 20 minutes. If your personal items can't be washed, place them in a sealed plastic bag for 5 to 7 days.

How long can dead nits stay in hair? ›

How long can dead nits stay in hair? Nits stick to the hair shaft. Hatched casings and dead nits can stay on the hair shaft for months, even after curing the lice infestation, unless you remove them manually. Because of this, finding nits alone doesn't always mean there's an active lice infestation.

How long can lice live on a hairbrush? ›

Head lice survive less than 1–2 days if they fall off a person and cannot feed; nits cannot hatch and usually die within a week if they are not kept at the same temperature as that found close to the scalp.

Can head lice live on pillows and sheets? ›

Head lice do not live on pillows or sheets, as they need to feed on the scalp of a host in order to survive. According to the CDC, lice can only survive for 48 hours after falling from a host scalp.

How long do you have to keep bagged stuff after lice? ›

However, although rarely necessary, some experts recommend that items that may be contaminated by an infested person and that cannot be laundered or dry-cleaned should be sealed in plastic bag and stored for 2 weeks to kill any lice that already are present or that might hatch from any nits that may be present on the ...

Do I need to clean my house after head lice? ›

After a lice infestation, it is good to thoroughly clean your home. Once you've ensured you or your family is free of head lice, you'll want to address any items in the house that may still harbor lice and eggs.

How long can nits live on bedding? ›

As with furniture and carpets, adult lice typically live for around 2 days on pillows and sheets without human contact. Nits will not hatch and will die within a week. People should machine wash any pillows or sheets someone with lice has used in hot water of more than 130°F (54.4°C) .

What are the CDC guidelines for lice in schools? ›

Students diagnosed with live head lice do not need to be sent home early from school; they can go home at the end of the day, be treated, and return to class after appropriate treatment has begun. Nits may persist after treatment, but successful treatment should kill crawling lice.

Does lice require isolation? ›

What precautions should I take at home if I have scabies or lice? Don't share personal items such as clothing, hats, combs, or hair accessories. Machine wash all of your personal items and clothing in hot water and place them in a hot dryer for at least 20 minutes.

Top Articles
Latest Posts
Recommended Articles
Article information

Author: Nicola Considine CPA

Last Updated:

Views: 6694

Rating: 4.9 / 5 (69 voted)

Reviews: 84% of readers found this page helpful

Author information

Name: Nicola Considine CPA

Birthday: 1993-02-26

Address: 3809 Clinton Inlet, East Aleisha, UT 46318-2392

Phone: +2681424145499

Job: Government Technician

Hobby: Calligraphy, Lego building, Worldbuilding, Shooting, Bird watching, Shopping, Cooking

Introduction: My name is Nicola Considine CPA, I am a determined, witty, powerful, brainy, open, smiling, proud person who loves writing and wants to share my knowledge and understanding with you.