If your child’s school no longer sends a child home the day head lice are found, it is following the CDC and the AAP. The CDC tells schools that “you do not need to send students with head lice infestation home early from school,” and the AAP agrees. The reason is medical: head lice carry no disease. What changed is who does the work. The finding, the treating and the weeks of follow-up now happen at home.
What the CDC and the AAP Say About Lice and the School Day
The reasoning behind both positions is that head lice are not a health threat. The CDC states that head lice do not transmit any disease and are therefore not considered a health hazard. The AAP, on its parent page about the signs of head lice, says that though head lice may be a nuisance, they do not cause serious illness or carry any diseases, and they do not put your child at risk for any serious health problems. The AAP also believes “a child should not miss or be excluded from school because of head lice.”
Lice are not a cleanliness problem, and the health agencies say so. The CDC’s overview of how head lice spread and survive says getting head lice is not related to the cleanliness of you or your environment, and the NIH’s MedlinePlus is blunter still: personal hygiene and cleanliness have nothing to do with getting head lice. Lice spread mainly by direct contact with the hair of a person who has them, and they crawl. They cannot hop or fly.
So nothing about the discovery has become less urgent for you. It has only become quieter. You get told, and every decision after that is yours to make.
The Part Worth Watching Is the Scratching
What deserves your attention is the scratching, not the insects. The CDC lists itching as the most common symptom of a head lice infestation and explains that it is an allergic reaction to louse bites. Scratching can leave sores on the head, and the CDC notes those sores can sometimes become infected with bacteria normally found on the skin. MedlinePlus describes the same chain of events.
Itching is not the only sign. The CDC lists a tickling feeling or a sensation of something moving in the hair, plus irritability and sleeplessness. MedlinePlus explains the sleep piece: head lice are most active in the dark. The AAP adds that itching caused by head lice can last for weeks, even after the lice are gone, and that most of the itching happens behind the ears or at the back of the neck.
None of that is an emergency, but it is the reason to act instead of wait. The scratching is the part to watch, and our post on whether head lice are dangerous covers it in more detail.
How to Tell Whether Your Child Has Live Lice Tonight
Finding a live nymph or adult louse on the scalp or in the hair is the best way to diagnose head lice, according to the CDC. Specks alone are weaker evidence, and the CDC says misdiagnosis of head lice infestation is common. The AAP is firm that head lice medicine should be used only when it is certain that your child has living head lice, and that you should check with your child’s doctor before beginning any treatment.
The AAP describes a comb-out check a parent can do at home:
- Seat your child in a brightly lit room and part their hair.
- Wet the hair, then comb through it in small sections with a fine-tooth louse or nit comb.
- After each comb-through, wipe the comb on a wet paper towel, then examine the scalp, the comb and the towel.
- Repeat until you have combed through all of your child’s hair.
It helps to know the sizes. An adult louse is roughly 2 to 3 mm long, about the size of a sesame seed, with a body the AAP describes as usually pale and gray, though the color may vary. A nymph is about the size of a pinhead. An egg is oval, about 0.8 mm long and 0.3 mm wide, yellow to white, and held firmly to the hair by a sticky substance. Live lice avoid light and move quickly, which is why the CDC suggests a magnifying lens along with the fine-toothed comb. Start at the hairline at the back of the neck and behind the ears, which the AAP calls the easiest place to find them.
| What you find | What the CDC and the AAP say it means |
|---|---|
| A crawling louse on the scalp or hair | Finding a live nymph or adult louse is the best way to diagnose an infestation (CDC). |
| Specks within 1/4 inch of the scalp | If you do not see crawling lice, look for nits attached firmly within 1/4 inch of the base of the hair shafts (CDC). |
| Specks more than 1/4 inch from the scalp | Those are almost always hatched or dead, and the infestation is probably old and does not need treatment (CDC). |
| Specks that flick off the hair | Nits are firmly attached to hair, while dandruff, dirt or other particles are not (AAP). |
| You cannot tell either way | If you are not sure if a person has head lice, see your healthcare provider (CDC). |
A head with no complaints at all can still be carrying lice. The CDC says people with head lice may not have symptoms, particularly with a first infestation or when an infestation is light, and that it may take four to six weeks for itching to appear the first time. That is why a child can carry lice for weeks before the itching starts. Our post on professional lice screening and a home check covers the difference.
Who Else in the House Gets Checked the Same Night
Everyone who lives in the house, plus close contacts. The CDC says to check all household members and other close contacts for head lice, and to treat all infested people, including anyone they share a bed with, at the same time. MedlinePlus gives the same instruction, and the AAP agrees that all household members and close contacts should be checked and treated if necessary.
The reason sits in how lice travel. The AAP says the main way head lice spread is close, prolonged head-to-head contact, and the CDC notes that this kind of contact can be common among children playing at places like school or the home. The CDC also reports that in the United States, infestation with head lice is most common among preschool- and elementary school-age children and their household members and caretakers. Shared objects matter far less: the AAP calls it a very small chance that head lice spread through combs, brushes, hats and sports helmets.
So a check that stops at the one child who was named is an incomplete check. The AAP recommends regular checks as a way to spot head lice before they have time to multiply. Teaching children to avoid head-to-head contact during play, and not to share combs, brushes, towels, hats, scarves, hair ribbons or barrettes, lowers the odds that the next round starts at all.
Why a Case You Already Treated Turns Up Again
A treated case can come back for several reasons. The CDC names the reasons treatment fails: misdiagnosis, recent application of a combination shampoo or conditioner to the hair, not following treatment instructions, head lice resisting the medication, and reinfestation after successful treatment.
Timing is where the eggs get their chance. The CDC’s guidance on treating head lice explains that some medicines kill lice and eggs, in which case retreatment is usually not required, while others kill lice but not eggs, in which case you treat again about a week after the first treatment, 7 to 9 days depending on the drug. A second treatment should go on after all the eggs have hatched but before new eggs are produced. The CDC puts hatching at about a week, a range of 6 to 9 days, with nymphs taking about seven days after that to mature. Which medicine you have sets your calendar, so the label and your child’s doctor decide that date.
The CDC is equally clear about restraint. If you notice a few lice still moving slowly 8 to 12 hours after treatment, you do not need to reapply the medicine. Treat again only if there are live, crawling lice several days later, and talk to your healthcare provider before re-treating. Do not treat more than two or three times with the same medication if it is not succeeding. Nits may stay in the hair after treatment, but successful treatment will kill crawling lice.
Resistance is real and local. The AAP says head lice can be resistant to the active ingredients in over-the-counter treatments in some communities, that the likelihood of resistance varies across the country, and that it is best to call your pediatrician before treatment. The AAP has also observed that parents sometimes treat their children up to five times before asking for that help. Our post on lice shampoo and the lice cycle goes further.
Follow-up checks matter too. The CDC says to check the hair and remove nits and lice every 2 to 3 days for the next 2 to 3 weeks after each treatment, and the AAP says the comb-out method usually does not work on its own to get rid of head lice. Left alone, the AAP warns, the cycle can repeat every three weeks. That gap between a single bottle and the full set of follow-up checks is what decides whether you are done. Our post on the lice removal process lays it out.
Frequently Asked Questions
When can kids with lice go back to school?
The CDC says a child with head lice can go home at the end of the day, be treated, and return to class after beginning appropriate treatment. The AAP’s position is that a child should not miss or be excluded from school because of head lice. The follow-up checks still belong to the two to three weeks that come after.
Do I have to deep clean the whole house?
No. The CDC says spending much time and money on housecleaning activities is not necessary. It suggests machine washing and drying the clothing, towels and bed linens used in the two days before treatment, on the hot water cycle at 130 degrees Fahrenheit with high heat drying. Seal what you cannot wash in a plastic bag for two weeks, soak combs and brushes in hot water for 5 to 10 minutes, and vacuum where the person sat or lay.
Can my child catch lice in a swimming pool?
It is unlikely. The CDC says head lice can survive under water for several hours but are unlikely to spread in a swimming pool, and that chlorine levels in pool water do not kill head lice. The CDC also tells families not to share towels, combs or brushes. Hair-to-hair contact in the water is still contact.
Can our dog or cat give the kids lice?
No. The CDC states that animals do not get or spread head lice. These are human parasites that feed on human blood, and the CDC says they will die within two days if they fall off a person and cannot feed. One pet aisle item does help, though: the CDC notes that flea combs made for cats and dogs are also effective for removing lice and nits.
Do mayonnaise, olive oil or other home remedies work?
There is no evidence they do. The CDC says there is no scientific evidence that suffocating head lice with mayonnaise, olive oil, margarine, butter or similar substances is an effective treatment, and the AAP says the same about petroleum jelly, tub margarine and essential oils because no studies prove they work. Never use gasoline or kerosene, which are dangerous and flammable, and never place a plastic bag on a child’s head.
Should I spray the house or set off a lice fog?
No. The CDC says not to use fumigant sprays or fogs, that they are not necessary to control head lice, and that they can be toxic if inhaled or absorbed through the skin. The AAP also says not to spray pesticides in your home, because they can expose your family to dangerous chemicals and are not needed when the scalp and hair are treated properly.
How do I know whether the treatment worked?
Look for dead lice. The CDC says that if you do not find any dead lice, or the lice seem as active as before treatment, the medicine may not be working, and it tells you to talk to a healthcare provider, who may suggest a different medicine. The AAP says to check with your child’s doctor before beginning a second or third medicine. Do not use two different lice drugs at the same time unless a provider or pharmacist tells you to.
How Lice Lifters of Bucks County Can Help
If you would rather not spend the evening squinting at a hair shaft, bring it to us. A visit to our clinic includes a check of the whole family. Our professional lice treatment is non-toxic and finishes in one visit, and we hold same-day appointments for the days when a note arrives with no warning. The 30 Day Guarantee applies when the whole family is checked. We leave prescriptions and medicine labels to your pediatrician. When you are ready, book an appointment and we will take it from there.
