A head louse on hairOxford Scientific—Getty Images
by
Dominique Mosbergen
Health correspondent
Sep 9, 2026 10:15 AM ET
As children return to school, families have a lot to look forward to: fresh routines, new connections, crisper weather—and a greater risk of head lice.
September is National Head Lice Prevention Month in the U.S, coinciding with a time of year when infestations tend to surge. “Head lice can occur throughout the year, but cases are often noticed more frequently in late summer and early fall, when children return to school and resume close-contact activities,” says Dr. April Armstrong, chief of dermatology at the University of California, Los Angeles.
Head lice is a common childhood condition, with up to 12 million head lice infestations occurring among children ages 3 to 11 every year in the U.S., according to estimates from the U.S. Centers for Disease Control and Prevention (CDC).
The insects don’t spread disease, but they can still cause a great deal of distress, doctors say. “Having head lice is not a sign of poor hygiene, but it can cause stress and anxiety because there is this stigma that it is,” says Dr. Carla Torres Zegarra, a pediatric dermatologist at Children’s Hospital Colorado. “If left untreated, it can also be very bothersome, causing itching and disturbing sleep.”
Here’s what to know about the pesky parasites, and how to spot, treat, and prevent them.
What are head lice?
Head lice, or Pediculus humanus capitis, are tiny, wingless insects that feed on human blood. They are found mostly on the scalp, but sometimes appear on eyebrows and eyelashes.
Adult head lice are about the size of a sesame seed and are usually tan to grayish-white in color, according to the American Academy of Pediatrics (AAP). Head lice lay and attach their eggs—known as nits—to the base of hair shafts using a glue-like substance. Infested people may have a combination of adult and juvenile head lice, nits, and empty egg casings on their scalp and in their hair.
Are they the same as pubic or body lice?
No. There are three different types of lice that feed exclusively on humans: head lice, pubic or “crab” lice, and body lice. Unlike head lice, which have elongated bodies, pubic lice have short and round bodies, resembling crabs. Pubic lice typically spread through sexual contact and are most common in adults.
When people have body lice, the insects are found primarily on their clothing and bedding, and sometimes on their bodies. Unlike head lice, body lice is connected to hygiene practices and access to clean clothing, and spread primarily through direct contact with someone who has body lice or with their contaminated clothing or bedding. In the U.S., body lice mostly affects people without access to housing, clean clothes, and regular bathing, CDC says.
How do head lice spread?
Since head lice can only crawl and not jump or fly, they typically spread via head-to-head contact. “That’s why it happens more in kids, because they play in close proximity,” Torres Zegarra says.
Head lice can also spread through objects that touch the head, such as combs, hats, helmets, and pillowcases. But this type of indirect transmission is much less likely since head lice typically survive for less than a day when away from the scalp, and nits can’t hatch at temperatures cooler than that of the human scalp, AAP says.
by
Dominique Mosbergen
Health correspondent
Sep 9, 2026 10:15 AM ET
As children return to school, families have a lot to look forward to: fresh routines, new connections, crisper weather—and a greater risk of head lice.
September is National Head Lice Prevention Month in the U.S, coinciding with a time of year when infestations tend to surge. “Head lice can occur throughout the year, but cases are often noticed more frequently in late summer and early fall, when children return to school and resume close-contact activities,” says Dr. April Armstrong, chief of dermatology at the University of California, Los Angeles.
Head lice is a common childhood condition, with up to 12 million head lice infestations occurring among children ages 3 to 11 every year in the U.S., according to estimates from the U.S. Centers for Disease Control and Prevention (CDC).
The insects don’t spread disease, but they can still cause a great deal of distress, doctors say. “Having head lice is not a sign of poor hygiene, but it can cause stress and anxiety because there is this stigma that it is,” says Dr. Carla Torres Zegarra, a pediatric dermatologist at Children’s Hospital Colorado. “If left untreated, it can also be very bothersome, causing itching and disturbing sleep.”
Here’s what to know about the pesky parasites, and how to spot, treat, and prevent them.
What are head lice?
Head lice, or Pediculus humanus capitis, are tiny, wingless insects that feed on human blood. They are found mostly on the scalp, but sometimes appear on eyebrows and eyelashes.
Adult head lice are about the size of a sesame seed and are usually tan to grayish-white in color, according to the American Academy of Pediatrics (AAP). Head lice lay and attach their eggs—known as nits—to the base of hair shafts using a glue-like substance. Infested people may have a combination of adult and juvenile head lice, nits, and empty egg casings on their scalp and in their hair.
Are they the same as pubic or body lice?
No. There are three different types of lice that feed exclusively on humans: head lice, pubic or “crab” lice, and body lice. Unlike head lice, which have elongated bodies, pubic lice have short and round bodies, resembling crabs. Pubic lice typically spread through sexual contact and are most common in adults.
When people have body lice, the insects are found primarily on their clothing and bedding, and sometimes on their bodies. Unlike head lice, body lice is connected to hygiene practices and access to clean clothing, and spread primarily through direct contact with someone who has body lice or with their contaminated clothing or bedding. In the U.S., body lice mostly affects people without access to housing, clean clothes, and regular bathing, CDC says.
How do head lice spread?
Since head lice can only crawl and not jump or fly, they typically spread via head-to-head contact. “That’s why it happens more in kids, because they play in close proximity,” Torres Zegarra says.
Head lice can also spread through objects that touch the head, such as combs, hats, helmets, and pillowcases. But this type of indirect transmission is much less likely since head lice typically survive for less than a day when away from the scalp, and nits can’t hatch at temperatures cooler than that of the human scalp, AAP says.
Getting head lice has nothing to do with personal hygiene or the cleanliness of the environment, and is caused solely by exposure to an infested person.
If there’s an outbreak of lice at your child’s school or daycare, that’s not a guarantee they’ll get it. Though head lice frequently spread in schools, research has found that head lice actually have a low contagion rate in classrooms. That’s why the CDC, AAP, National Association of School Nurses and other medical groups don’t recommend keeping children with head lice away from school.
Animals don’t get or spread head lice.
How do you know if you or your child has head lice?
An itchy scalp is the most common symptom of head lice, “particularly behind the ears and near the back of the neck,” Armstrong says. “Some people also describe a tickling sensation or the feeling that something is moving in the hair. Scratching may produce redness, small sores, or, occasionally, a secondary bacterial infection.”
People can have head lice without symptoms, too. “With a first infestation, itching may not begin for four to six weeks because it takes time for the body to develop an allergic response to louse saliva,” Armstrong says.
Examining the hair and scalp under bright light and finding live crawling lice is the best way to diagnose a head lice infestation. Using a magnifying glass or a special lice comb can help with this process, AAP says. “Nits located farther from the scalp are often empty or no longer viable, so their presence alone does not necessarily indicate an active infestation,” Armstrong says.
Misdiagnosis of head lice is common. “Many presumed lice and nits submitted by physicians, nurses, teachers, and caregivers to a laboratory for identification were found to be artifacts such as dandruff, hairspray droplets, scabs, dirt, or other insects,” such as those blown by the wind and caught in the hair, AAP says.
The CDC recommends that people visit a doctor if they suspect they may have lice.
Who is at risk of head lice?
Head lice infestations most commonly occur in preschool- and elementary school-age children and their families.
Research suggests that girls may get head lice more often than boys. But the AAP says head lice infestations do not appear to be influenced by hair length, hair type, and frequency of shampooing or brushing.
How do you treat head lice?
There are several over-the-counter and prescription medications approved by the U.S. Food and Drug Administration (FDA) to treat head lice, including lotions and shampoos that contain the insecticides permethrin or pyrethrin. Treatment of head lice often involves using one of these medications, combined with “careful combing using a fine-toothed lice comb,” Armstrong says.
Some of these medications kill only lice, while others target both lice and nits. Depending on the medication, a second application may be needed seven to ten days after the first treatment, Armstrong says.
In some cases, head lice can be resistant to these topical medications, AAP says. In those situations, manual removal of lice and nits might be necessary—an option also available to people who want to avoid insecticide-containing products. The AAP says home remedies such as using mayonnaise, melted butter, or olive oil could work to suffocate the lice, though these methods are not FDA approved or recommended, and more research still needs to be done on their effectiveness. A prescription oral medication can also be used.
Some internet sites recommend using essential oils and other botanical products to kill head lice, but the AAP says “the safety and efficacy of natural or herbal products are currently not regulated by the FDA, and until more data are available, their use in infants, children, and adolescents should be avoided.” The AAP also stresses that head lice treatment is only recommended for people “in whom diagnosis is highly suspected or proven.”
Torres Zegarra says she sometimes sees patients with itchy scalps who developed irritation because they tried head lice treatments despite not having any evidence of lice. “What I end up treating is not lice but the skin irritation caused by multiple treatments that were tried on the scalp,” she says.
Doctors say that cutting or shaving the hair of an infested person isn’t necessary, and it does not always work to get rid of head lice.
“Long or very thick hair may require more product and more time to comb thoroughly, but it can be treated successfully without removing the hair,” Armstrong says. “If live lice remain after treatment has been used correctly, a clinician should determine whether the cause is medication resistance, reinfestation, or an incorrect diagnosis before additional treatments are applied.”
How do you prevent head lice?
“There is no completely reliable way to prevent head lice, especially among young children who naturally play in close contact. The most effective step is to limit direct head-to-head or hair-to-hair contact when lice are known to be circulating,” Armstrong says.
If someone is confirmed to have head lice, members of their household and other close contacts should be carefully checked for infestation. “Clothing, towels, and bedding used during the two days before treatment can be washed and dried using heat,” Armstrong says. “Combs and brushes can be soaked in hot water. Extensive cleaning, fumigation, and pesticide sprays are unnecessary.”
AAP says parents and other caregivers could check children regularly to catch and treat early infestations, and children can be taught not to share personal items such as combs and hats. They shouldn’t refuse to wear helmets because of fear of head lice, however, particularly since the spread of lice through objects is uncommon, AAP says.
Ultimately, Torres Zegarra says “there’s no need to panic” when head lice arise. “It’s a nuisance problem but not a health crisis,” she says, adding that children with head lice shouldn’t be quarantined or kept away from school.
“No healthy child should lose out on education because of head lice. They should avoid head-to-head contact, but they shouldn’t be shamed or isolated,” Torres Zegarra says.
Some of these medications kill only lice, while others target both lice and nits. Depending on the medication, a second application may be needed seven to ten days after the first treatment, Armstrong says.
In some cases, head lice can be resistant to these topical medications, AAP says. In those situations, manual removal of lice and nits might be necessary—an option also available to people who want to avoid insecticide-containing products. The AAP says home remedies such as using mayonnaise, melted butter, or olive oil could work to suffocate the lice, though these methods are not FDA approved or recommended, and more research still needs to be done on their effectiveness. A prescription oral medication can also be used.
Some internet sites recommend using essential oils and other botanical products to kill head lice, but the AAP says “the safety and efficacy of natural or herbal products are currently not regulated by the FDA, and until more data are available, their use in infants, children, and adolescents should be avoided.” The AAP also stresses that head lice treatment is only recommended for people “in whom diagnosis is highly suspected or proven.”
Torres Zegarra says she sometimes sees patients with itchy scalps who developed irritation because they tried head lice treatments despite not having any evidence of lice. “What I end up treating is not lice but the skin irritation caused by multiple treatments that were tried on the scalp,” she says.
Doctors say that cutting or shaving the hair of an infested person isn’t necessary, and it does not always work to get rid of head lice.
“Long or very thick hair may require more product and more time to comb thoroughly, but it can be treated successfully without removing the hair,” Armstrong says. “If live lice remain after treatment has been used correctly, a clinician should determine whether the cause is medication resistance, reinfestation, or an incorrect diagnosis before additional treatments are applied.”
How do you prevent head lice?
“There is no completely reliable way to prevent head lice, especially among young children who naturally play in close contact. The most effective step is to limit direct head-to-head or hair-to-hair contact when lice are known to be circulating,” Armstrong says.
If someone is confirmed to have head lice, members of their household and other close contacts should be carefully checked for infestation. “Clothing, towels, and bedding used during the two days before treatment can be washed and dried using heat,” Armstrong says. “Combs and brushes can be soaked in hot water. Extensive cleaning, fumigation, and pesticide sprays are unnecessary.”
AAP says parents and other caregivers could check children regularly to catch and treat early infestations, and children can be taught not to share personal items such as combs and hats. They shouldn’t refuse to wear helmets because of fear of head lice, however, particularly since the spread of lice through objects is uncommon, AAP says.
Ultimately, Torres Zegarra says “there’s no need to panic” when head lice arise. “It’s a nuisance problem but not a health crisis,” she says, adding that children with head lice shouldn’t be quarantined or kept away from school.
“No healthy child should lose out on education because of head lice. They should avoid head-to-head contact, but they shouldn’t be shamed or isolated,” Torres Zegarra says.
