What do lice eat?

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8 Facts for Parents – What to Know About Head Lice

It’s the time of year when kids gather in school. They’re building friendships, sharing curiosity and… yep, sometimes swapping head lice. It can happen in any school with any kids. Personal hygiene and home or school cleanliness has nothing to do with head lice or their spread.

If you have children, you may already be familiar with head lice. Head lice infestations are common in pre-schools and elementary schools. They can spread around to everyone in a household, regardless of age.

Getting Acquainted with… Head Lice

Head lice are small parasitic insects. They live on the scalp. They like the areas behind and around ears and near the neckline at the back of the head. Sometimes they can be in the eyelashes or eyebrows, but that’s uncommon.

Lice start as eggs, or nits, that are tiny. Nymphs hatch from eggs. Nymphs look like a small version of the adult. The adult louse (singular for lice) is about the size of a sesame seed. It has six legs and is tan to light gray.

Females are bigger than the males and can lay about six eggs every day. An adult louse can live up to 30 days on a person. They live only a couple of days when not on a person. Lice feed on human blood to live.

How Do Head Lice Get Around?

These bugs cannot hop or fly. They typically crawl from person to person when head-to-head contact is made. It’s less common but they can also move from person to person when clothing, hats, scarves, combs, brushes, towels or plush toys are shared.

What Are the Signs of Head Lice?

The Centers for Disease Control and Prevention (CDC) says a person with head lice may notice:

  • A tickling feeling of something moving in the hair. That happens because there is something moving in the hair. (You’re right, that’s a little gross.)
  • Itching. This can be caused by an allergic reaction to a louse bite.
  • Irritability and trouble sleeping. This can happen because head lice are most active in the dark.
  • Sores on the head caused by scratching. The sores can become infected by bacteria found on the skin. (Saying “ewwwww” now would be totally understandable.)

OK, Let’s Bring Up Some Good News

The good news is: Head lice are not considered a medical or public health hazard by the CDC. And they are not known to spread disease.

Dogs, cats and other pets do not seem to help spread head lice. That’s another reason to love your pet.

For the most part, head lice are spread by simple contact between people. If you can avoid close contact, you can reduce the risk of spreading the little pests.

Cases of shared sports helmets spreading head lice are rare. The feet of head lice are adapted to hang onto hair, but they tend to fall off surfaces such as plastic, metal, polished synthetic leathers and such.

How to Get Rid of Head Lice

The first step in dealing with head lice is accepting that their presence is not a reflection on you as a parent. They’re just little critters doing what they were made to do. Your family just happened to be in their path.

If you suspect head lice, check everyone in your household, especially those who share a bed. You can check for head lice by using a special metal “nit comb.” It allows you to part the hair for a good look at the scalp of a person who may have head lice.

If you need to check for lice, be patient. And remember to check the areas we mentioned that lice prefer — by the ears and above the back of the neck.

If you find nits or lice, you can manually remove them with fingernails. The nits attach to hair using a cement-like substance. Don’t be surprised if it takes some effort to work them loose. Again, patience is an advantage for this project. And thoroughly wash your hands when you’re done.

Do not share items such as hats, towels and grooming aids used by the person affected by lice.

Scalp Treatments

As a next step, you can treat head lice with a home remedy or an over-the-counter (OTC) medicated shampoo. You can search “home remedy for head lice” online.

If you’d like to try an OTC medication, you’ll want to look for products containing pediculicides (medicines that kill lice). Look for medications that contain pyrethrins or permethrin. These products are designed to kill the eggs.

If you’re not sure about which product(s) to choose, ask your health care provider or pharmacist for recommendations.

Thoroughly read and carefully follow directions for these products. Not all products are the same, so review application and re-application instructions for each product.

Keep all these products out of eyes. If they get in the eyes, immediately rinse the eyes.

If one over-the-counter product doesn’t work, try another with a different active ingredient. If these efforts do not resolve the issue, see your health care professional. Prescription medications are available for problematic cases.

Prevent Re-infestations

Immediately after treatment, the person you’ve treated should put on clean clothing.

Gather items such as hats, scarves, pillowcases, bedding, clothing and towels used by people with lice. Gather things they used in the two days before treatment.

Wash the items in water 130 degrees or warmer. The items should be in the water at least five minutes. Then dry on a hot air cycle.

If an item can’t be laundered, it can be dry cleaned or sealed in a plastic bag for two weeks.

Soak combs and hairbrushes in water that’s at least 130 degrees for five to 10 minutes.

Vacuum furniture and floors. This can pick up hairs that may have nits attached.

There… that’s probably all you’d ever want to know about head lice. Oh, there’s one more thing.

Other Types of Lice

Along with head lice, there’s also:

  • Pubic lice. Also called crabs. They’re found in the pubic area, and sometimes on eyelashes, eyebrows, under arms and on chest hair. They’re rarely found on the scalp.
  • Body lice. They live and lay their eggs (nits) in clothing seams. They crawl to the body to feed.

Treatment for other types of lice are similar to head lice. The other types of lice are less common.

Still Have Questions?

If you have questions about dealing with lice, visit with a health care professional. You can schedule an appointment online or try E-Care Consultation. A pharmacist is another helpful resources.

Lice are aggravating, but you can work your way through this nuisance.

Head Lice Facts 101: Do’s & Don’ts

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Let’s start by establishing some facts about head lice:

HEAD LICE ARE

  • 1 of the top 3 reasons kids miss school.
  • Extremely common! Between 6-12 million U.S. kids 3-11 years old get head lice each year.
  • Not dangerous, but are contagious (and annoying).
  • NOT signs of unwashed or unclean hair. They thrive in clean hair!
  • Unable to jump, fly or swim.
  • Unable to live on your pets.
  • Unable to live in your environment (couch, carpet, furniture, pillow, sheets, mattress, car, movie theater, airplane).

LICE DO’S

  • Use proven, manual head lice removal methods and all-natural products.
  • Daily wash only the clothing, bedding, brushes, and hair accessories used during your head lice infestation.
  • Screen your entire household as soon as one child has head lice.
  • Tell your school and friends you have head lice to avoid cross-pollination. Spread the word, not the lice!
  • Relax and take a deep breath!

LICE DON’TS

  • Don’t replace your furnishings (including your mattress).
  • Don’t wash your entire wardrobe.
  • Don’t use toxic products or ineffective home remedies for head lice. Some over-the-counter shampoos can be highly toxic (especially for kids), yet many strains of lice are immune to the chemicals.
  • Don’t cut your hair or pour olive oil, mayonnaise, Listerine, tea tree oil, vinegar, Vaseline, or gasoline on it — these methods don’t work. Some are dangerous; others are better used as a preventative measure or in tandem with a lice comb.
  • Don’t panic! Hair Fairies is here to help! Call us at 877-285-0069.

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THE LIFE CYCLE OF A LOUSE

Illustration and info with thanks to Centers for Disease Control and Prevention (CDC).

EGGS
Head lice eggs (called “nits”) are hard to see and often confused for dandruff or hair spray droplets. Nits can be found at the base of the hair shaft nearest the scalp (1).

NYMPHS
The egg hatches to release a nymph (2). The nit shell then becomes a more visible dull yellow and remains attached to the hair. Nymphs mature after three molts (3, 4) and become adults about seven days after hatching.

ADULTS
The adult louse has six legs, each with a claw, and is tan to grayish-white (5). In people with dark hair, the adult louse will appear darker. Adults multiply quickly, laying up to eight eggs a day, and living up to 30 days on someone’s head. A louse can go two days without blood meals.

If you suspect someone in your family has head lice, act quickly to prevent these parasites from spreading!

Come into a kid-friendly Hair Fairies salon, or call us, and we will be more than happy to help.

DIY TREATMENT VIDEOS

We are determined to help you manage your head lice. Our number one mission at Hair Fairies is to help families help themselves.

We have packed more than a decade of experience into our free, step-by-step tutorial. In this and our other how-to videos, you will learn how to identify a head lice egg and adult head lice. You will also get easy-to-follow tips on head lice treatment and prevention products.

  • Step-by-Step Tutorial – Head Lice Treatment: The Safe and Natural Way
  • Get Rid of Head Lice: An Introduction to Hair Fairies Products
  • Hair Fairies: the Head Lice Helpers

Ready? Watch our lice treatment videos!

Questions? Concerns? Visit our DIY section or call the free Hair Fairies hotline at 877-285-0069.

PREVENTION TIPS

The sooner head lice are detected, the better. Quick action and preventive measures can minimize their spread and chance of returning.

Parents Preventative Measures:

  • Screen your child for head lice once a week.
  • Be extra vigilant after returning from any school, camp, or holiday break (places where outbreaks tend to occur more often).
  • Promote lice screenings at your school/camp — they will help limit outbreaks.

If you hear of a lice outbreak:

  • Keep long hair pulled back in a braid or ponytail. (Long hair is more susceptible to lice.)
  • Apply Hair Fairies Nit-Zapping™ Clenz Prevention Oil onto scalp.
  • Spray Hair Fairies Nit-Zapping™ Lice Repellant Spray on your non-washables at home, such as your kids’ backpacks and sports caps.

If you find head lice on your child:

  • Notify your school, friends, and family immediately to help curtail spread.
  • Wash all affected clothing with Hair Fairies Laundry Detergent.
  • Use Hair Fairies all-natural Nit-Zapping™ Clenz Cream and Nit-Zapping™ Lice Comb to remove lice, then treat with Nit-Zapping™ Clenz Shampoo. Or come to a Hair Fairies salon near you.
  • Wash your family’s hands with Hair Fairies Foaming Eucalyptus Hand Soap to prevent transfer of head lice.

SCHOOLS/CAMPS

  • Screen your school/camp for lice once a month.
  • Remove any negative stigma attached to contracting head lice by educating families and staff, and by promoting speedy notification of parents.
  • Use Hair Fairies Nit-Zapping™ Lice Repellant Spray in your school/camp environment, such as on stuffed animals, pillows, uniforms, and caps.
  • Use Hair Fairies Foaming Eucalyptus Hand Soap to prevent transfer of head lice.

Still have questions?
Give us a call at 877-285-0069 or contact our lice removal salons for assistance.

What Are Head Lice?

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Scratch scratch. Scratch. Your head is feeling really itchy. Could it be lice?

If so, you’re not alone. Every year, millions of people worldwide get head lice. Most of those millions are kids. Any kid who goes to school has probably already heard about lice. They can spread easily at schools, so if one kid gets them, the rest of the class might get them, too. What can you do? Let’s find out.

Lice are very, very small insects. In fact, they are so tiny that you can barely see them! Each louse (the name for one of the lice) is only about the size of a sesame seed.

Head lice need to be next to skin to survive — and the warmth of your skin is a perfect place for them to live. Lice eat tiny amounts of blood (much less than a mosquito does) for their nourishment and use their sticky little feet to hold on to hair. Gross!

When lice start living in hair, they also start to lay eggs, or nits. Lice can survive up to 30 days on a person’s head and can lay eight eggs a day. Lice attach their nits to pieces of hair, close to the scalp. If you see a small, oval blob on a strand of hair, that’s probably a nit. If these little eggs are yellow, tan, or brown, the lice haven’t hatched yet. If the eggs are white or clear, the lice have hatched.

Although they don’t hurt, lice sometimes can irritate the skin and make it itchy (especially at night). Too much scratching can lead to scalp infections.

Head Lice Love Everyone

Having lice can be embarrassing, but anyone can get them. That includes the cleanest kid in the class! Having head lice is not a sign of dirtiness or poor hygiene. The pesky little bugs can be a problem no matter how often a kid does — or doesn’t — wash their hair or take a bath.

Lice can’t jump or fly. They spread when people’s heads touch or when they share hats and other clothing, combs, brushes, headbands, barrettes, and bedding (like sheets, blankets, pillowcases, and sleeping bags). If lice are stuck on any of these things and that thing touches another person’s head, that person may also get lice. Lice spread in classrooms and schools because kids play together closely and often share more stuff than adults do.

How Can We Get Rid of Head Lice?

If your head feels very itchy, tell an adult as soon as possible. This is especially true if you know that other kids in your class or school have had lice. Don’t wait around — the more time the lice have to lay nits, the itchier you will be!

Often a parent or school nurse can recognize head lice just by looking for nits in the hair. Some kids’ parents will take them to the doctor so the doctor can check to see if lice are there.

Medicine

If a kid has lice, an adult will need to buy a special medicated shampoo, cream, or lotion that kills lice. An adult will need to apply the medicine and follow the directions. Part of the treatment is combing your hair with a fine-tooth comb to remove the nits. The shampoo, cream, or lotion usually kills the lice right away. The itching should go away within a few days, but treatment may need to be repeated in 7 to 10 days to kill any new lice that may have hatched since the first treatment.

Do not use a hair dryer on your hair after washing with the medicated shampoo, lotion, or cream because they can contain flammable ingredients. You don’t want your hair catching on fire.

Removing By Hand

Your parent also can try removing the nits and lice by hand. To do this, your mom or dad will use a fine-tooth comb on your wet, conditioned hair every 3–4 days for 3 weeks after the last live louse was seen. Wetting the hair temporarily stops the lice from moving, and the conditioner makes it easier to get a comb through the hair.

Although lice can live for only 1 to 2 days off a person’s head, it’s a good idea for an adult to wash all your bedding, hats, clothing, and stuffed animals in hot water. Or they can seal these things in airtight bags for 2 weeks. That also will kill the lice and their eggs.

Vacuuming the carpets, upholstery, and car seats will take care of any lice that fell off before treatment. Combs, brushes, and hair accessories need to be soaked in hot water, washed with medicated shampoo, or thrown away.

Sometimes it’s hard to get rid of the lice. If that happens to you, have your parent talk to the doctor. There are stronger medicines and other treatments that they may decide to use.

Life Without Lice

Sure, lice aren’t so nice, but there are things you can do to keep them away. To help prevent lice:

  • If your friend has lice, don’t give the lice any chance to spread to you. Avoid putting your heads together or sharing stuff that could contain lice, such as hats or combs.
  • Don’t try on hats that belong to other kids.
  • Never share a comb, brush, barrettes, or other hair accessories. Use your own, and don’t lend them to anyone else.
  • Always use your own sleeping bag and pillow when sleeping away from home.

Sharing is usually a great idea — except when you’re sharing lice!

Reviewed by: Michelle P. Tellado, MD Date reviewed: September 2019

How do you know if you’ve got head lice?

According to Public Health England (PHE), the only reliable way to diagnose an active infestation is to find a living, moving louse. This is because the eggs of lice (nits) can be mistaken for dandruff or hair muffs – oily secretions that can wrap around hair – and even if you do find a nit, it is difficult to tell whether it is dead or alive. Not everyone with head lice will experience an itchy scalp, and itchiness could be psychological, or the result of something else, such as eczema. The best way to find a living louse is through combing: it’s nearly four times more effective than simply ruffling through the hair and spotting one with the naked eye.

Do I need an expensive comb?

Many combs marketed for the removal of lice or nits aren’t fit for purpose, says Ian Burgess, president of the International Society of Phthirapterists (people who study lice): “Either the teeth are too far apart; they’re constructed from flimsy plastics; or they have inconsistently arranged teeth.” The ideal detection comb is a plastic one with flat, parallel teeth less than 0.3mm apart. There is no evidence that double layers of teeth or electric combs are more effective, Burgess says.

Combing should be performed on damp hair, in good light, and applying conditioner makes it easier. Start at the top of the head with the teeth of the detection comb touching the scalp, and gently draw the comb downwards, looking carefully at the teeth for the sesame seed-sized insects.

I’ve found a louse – what do I do now?

Many of the treatments you’ll find in your chemist are based on an oily substance called dimeticone. This physically blocks the holes through which lice breathe, suffocating them – rather than poisoning them, as older insecticides such as permethrin or malathion did. “Some populations of head lice have developed resistance against insecticides, so these tend not to be the best treatments anymore,” says James Logan, scientific director of the Arthropod Control Product Test Centre at the London School of Hygiene and Tropical Medicine. Because dimeticone acts as a physical barrier, lice are unlikely to develop resistance to it, but it still only works around 80-90% of the time. The key is to thoroughly soak the hair with product, and then re-treat a week later to catch any newly hatched lice.

What about non-chemical treatments?

You could try wet-combing with conditioner and a series of fine-toothed combs, such as those found in so-called “bug buster” kits. Done properly, this clears head lice in 57% of cases, but it involves thoroughly combing the hair four times in the space of two weeks. For long, curly hair, this could mean 30 minutes each time. “Most caregivers are not that dedicated,” Burgess says.

Companies exist that will physically remove head lice using a kind of vacuum cleaner. “With big infestations, this can be a good way to at least bring numbers down, and can be helpful if you can’t get other treatments to work,” says Logan. You could also try tea tree oil, which poisons lice – although it only seems to be effective at concentrations upwards of 10%, at which point it may start to irritate the skin. “Most tea tree shampoos and conditioners contain less than 1% tea tree oil so would have no effect on lice,” says Burgess.

My child refuses to let me comb her hair. What can I do?

“Unfortunately, one of the things small children dislike more than anything is having their hair combed,” says Wendy Nicholson, lead nurse for children, young people and families at Public Health England. She advises distraction techniques, such as getting someone to read them a story, as well as building combing into their regular routine. Engaging children in louse detection can prove effective: get children to comb their dolls’ hair for imaginary lice; suggest they write a story or shoot a film about them; if they like science, encourage them to look at dead lice through a magnifying glass. “Follow their interests,” Nicholson says.

Is it true that head lice can jump, and do they really prefer clean hair?

No; this idea may have come about because the static electricity generated through combing dry hair can cause lice to be flicked into the air. Neither can they swim, fly or hop – they walk from head to head, during physical contact. If they become detached from the head they are vulnerable, and their eggs need to be kept warm, so you’re also unlikely to catch head lice from bedding or from the backs of chairs. “Head lice usually feed on blood every five hours; if they’re removed from the head, they quickly start to become very ill and weak,” explains Logan.

As for preferring clean hair, “this is a myth created in the late 1970s to convince middle-class families that they too could catch lice,” says Burgess. “If your hair is gunked-up, lice don’t particularly like it, but they can survive as long as they can feed.”

My child keeps becoming infested: is there anything we can do to deter them?

There’s some limited evidence that tea tree and lavender oil repel head lice, but larger studies are needed, says Logan. The key things are to notify your child’s school if you detect head lice, encourage parents of close friends to check and treat their children, and regularly check your own child’s hair. “Detection at the earliest stage is most important,” says Burgess. Ideally, you want to kill lice before they get the opportunity to lay their eggs.

What’s Eating You? Head Lice (Pediculus humanus capitis)

The head louse (Pediculus humanus capitis) is a blood-sucking arthropod of the suborder Anoplura. Lice are obligate human parasites that have infested humans since antiquity. Pediculosis capitis is an infestation of the scalp by head lice. It is estimated that 6 to 12 million individuals in the United States are affected with head lice per year.1 Resistance to topical chemical pediculicides is widespread, and new agents have been developed to address this gap in care.

Characteristics of Head Lice

The head louse is a tan-gray–colored, wingless insect measuring approximately 2- to 3-mm long with 3 body segments. It has 6 legs with claws used to grasp individual hairs, and it moves by crawling; it does not fly or jump.2,3 The head louse has an elongated abdomen and a small head with short antennae and anterior piercing mouthparts (Figure 1).4 Nits are transparent, flask-shaped, 0.5- to 0.8-mm egg cases found firmly cemented to the hair shafts approximately 1 to 4 mm above the level of the scalp (Figure 2).5 The head louse resides on scalp hair and feeds off the scalp itself. Both lice and nits can be present throughout the scalp but are most commonly found in the postauricular and occipital scalp.3,4

Figure 1. Identifying characteristics of the head louse.

Figure 2. Hair shaft with an attached nit.

Female lice live approximately 30 days and lay 5 to 10 eggs per day. Eggs incubate individually in nits laid close to the scalp for 8 to 10 days before hatching.1,6 The newly hatched nymphs (also called instars) have multiple exoskeletons that are shed as they grow.7 Nymphs mature into adults in approximately 2 weeks, and the life cycle begins again.8 Head lice are obligate human parasites, feeding approximately every 4 to 6 hours on the blood of the host; however, they can survive up to 4 days without a blood meal on fomites if the climate and conditions are favorable.5,9

Epidemiology and Transmission

Head lice infestations commonly occur in children aged 3 to 11 years and are more prevalent in girls and women.1,10 Infestation rates are not reliably recorded, and few population-based studies have been performed; however, it is estimated that 6 to 12 million individuals are infested annually in the United States.1 Prevalence in some European populations has been estimated to range from 1% to 20%.11 A 2008 literature review found that worldwide prevalence varied across populations from 0.7% to 59%.10

Transmission occurs most frequently from direct head-to-head contact. One study found that transmission is most likely to occur when hairs are arranged in a parallel alignment and move slowly in relation to one another.12 Although controversial and probably less notable, transmission also may occur indirectly via fomites or the sharing of hairbrushes, hats, or other headgear.13,14 Classrooms are a common place for transmission.1 A 2009 study in Germany found an increase in health department consultations for head lice when schools reopened after vacations. The investigators also found that pediculicide sales peaked from mid-September through October, subsequent to schools reopening after the summer holiday.15 There is some evidence that overcrowded housing also can lead to increased incidence and transmission.16,17 There is no consistent correlation of infestation with socioeconomic status.1,17,18

Clinical Manifestations and Diagnosis

Clinically, patients with head lice present with scalp pruritus and sometimes posterior cervical or occipital lymphadenopathy. Pediculosis also can be asymptomatic. With the first exposure, symptoms may not develop for up to 4 to 6 weeks as the immune system develops sensitivity to the louse saliva.6 Bite reactions consisting of papules or wheals are related to immune sensitization.5 Louse feces and excoriations from scratching to relieve itch also may be present on examination. Secondary infection of excoriations also is possible.1

Diagnosis of an active infestation is made by identifying living lice. Because lice move quickly and can be difficult to detect, tightly attached nits on the hair shaft within 4 mm of the scalp are at least indicative of a historic infestation and can be suggestive of active infestation.1,19 Dermoscopy is a helpful tool in differentiating eggs containing nymphs from the empty cases of hatched lice and also from amorphous pseudonits (hair casts)(Figure 3).19,20 Wet combing improves the accuracy of diagnosing an active infection.21

Figure 3. Amorphous keratin forming a pseudonit on the hair shaft.

Lice: A-to-Z Guide from Diagnosis to Treatment to Prevention

My head starts to itch when I even write about lice. Lice are a common problem wherever children gather. If you are concerned about lice, you are not alone. Each year, many day-care centers, schools, neighborhoods, extended families, and small family units face this problem.

What is it?

Adult lice (also called Pediculus humanus capitis) are six-legged, wingless insects 2-4 mm long. They have translucent grayish-white bodies, and look a bit like a grain of rice with six legs.

Their heads have two tiny eyes (too small to be seen without magnification) and two small antennae (usually visible). Six pairs of hooks that surround the mouth allow them to attach themselves to the skin of the scalp for feeding. The mouth contains two retractable, needle-like tubes that pierce the scalp. Salivary juices are injected into the scalp to prevent blood from clotting, and then the lice feed happily, sucking blood through these same tubes. Their translucent bodies turn reddish brown when engorged with blood. Lice completely depend on the blood extracted from humans for existence, and thus will starve to death after 55 hours without blood.

Adult lice can freely move around a head of hair and travel to another person, clothing, plastic combs or brushes, or upholstered furniture. Adult lice usually live for about a month on a human host. During this time, the females generally lay from three to 10 eggs per day (although some female lice have been known to lay up to 5,000 eggs in their lives when in an environment to their liking).

Lice eggs are called nits. These white, translucent, pinpoint-sized eggs are laid near the base of hair shafts, and move outward as the hair grows (nits found near the tips of long hairs suggest a longstanding infestation). Nits are glued tightly to the side of the hair shafts, and cannot be moved along the shafts or knocked off with fingers. The eggs hatch between ten to fourteen days after they are laid. The empty eggs remain attached to the hair shaft. The newborn larvae must feed on human blood within 24 hours, or they will starve to death. The larvae become sexually mature adult lice within about one week. Adult head lice can survive up to two days away from the scalp, which is how they are transmitted by things like combs, brushes, and hats.

During this whole life cycle, larvae and adult lice deposit their feces in the scalp, which eventually causes itching as the person develops an allergic reaction to the lice stool.

Who gets it?

Lice seem to prefer children to adults, long hair to short hair, and they particularly like the hair of females. Interestingly, lice only rarely afflict African Americans living in North America. The lice in Africa and South America have adapted, however, and cases are common in every group on those continents. Cases of lice are most common in children 3 and 10 years old, but can occur at any age.

Lice have been a nuisance to humans since ancient times. Having head lice is not a sign of poverty or poor hygiene. They have thrived almost wherever humans have been in prolonged close contact with each other. One notable exception to this has been in areas where the pesticide DDT is in widespread use. In the United States, for a period of about 30 years, lice outbreaks were uncommon. Since DDT was banned in 1973, the number of cases of lice has risen steadily. Today, there are about 12 million cases per year in the United States alone.

What are the symptoms?

The hallmark symptom of head lice is itching, but a person may have lice for months before the itching begins.

Is it contagious?

Lice are quite contagious. They spread from person to person when heads touch. Because they can live independent of a person for up to 55 hours, they are also commonly spread via stuffed animals, hats, headphones, combs, brushes, towels, clothing, car seats, sofa cushions, and bedding.

How long does it last?

Each louse lives for about a month, but an infestation of lice will usually continue until treated.

How is lice diagnosed?

The best way to diagnose head lice is to inspect the head of anyone who might have been exposed to them using a bright light (full sun or the brightest lights in your home during daylight hours work well). A magnifying glass can make the job easier. Part the hair all the way down to the scalp in very small swaths, looking both for moving insects and nits. The entire head must be inspected to make sure there is no problem. Careful attention should be given to the nape of the neck and around the ears, the most common locations for nits. Even one nit in the hair should be treated. The egg might be empty, or contain a dead larva but then again, it might not!

Frequently, people find “pseudo-nits” and panic unnecessarily. Bits of hair spray, dead skin scales, or loose debris may be seen on hair shafts. These move with pressure from the fingers, and nits do not. Also, live nits glow when exposed to a black light (we use black lights in pediatric offices for inspection) and dead nits and empty nits do not.

How are lice treated?

Mechanical nit removal is the cornerstone of lice treatment, although medicines can be a real help.

The Great Lice Adventure

It is important for everyone potentially involved in an outbreak to be treated at the same time. If 99.99% of the lice are killed, but .01% are not, you already have the makings of another outbreak!

Here is a step-by-step guide for using common, over-the-counter medicines to kill the lice, followed by several great natural remedies:

  • Set a community-wide time to act — now!
  • Get all the kids excited about The Great Lice Adventure! Have teachers do projects on lice as insects. The more the kids know about what’s going on, the better. Use art, storytelling, science, even math. Start with one louse and calculate how many lice would be on an untreated head at the end of, say, a day, a week, a month …
  • Print detailed instructions on how to get rid of lice and distribute them to children, parents, teachers, and anyone else who works at the school.

Day One

Not all of the following steps are always necessary for an individual child. For stubborn cases, especially during school-wide outbreaks, following all of the steps can actually save a lot of hassle and repeated exposure to pesticides

  • Carefully comb through the hair using a nit comb. I don’t recommend using the combs that come packaged with lice shampoos. Instead, use a new product, called the LiceMeister. Its metal teeth are very close together, catching lice well, but without catching or pulling on hair. Since most children will only sit still for a short time (and since most parents don’t want to spend longer than necessary combing through lousy hair), using this comb results in a more thorough delousing than when using the ordinary plastic nit combs.
  • Recent studies show that while white vinegar does loosen nits from the hair shaft, it does not kill adult lice and is probably not sufficient when used alone.

Using stronger pesticides can set up a pattern of using more and more powerful pesticides as the lice develop ever-increasing resistance. This pattern has a definite negative long-term impact on the environment. It also exposes children to greater and greater levels of toxins.

Most alternative treatments are untested, but early reports are promising. One method with widespread stories of success is the Vaseline (or mayonnaise) treatment. Cover the infested head liberally in Vaseline. Place a shower cap over the entire head for the night (or an eight-hour period). Then shampoo the Vaseline out of the hair. This treatment is reported to “smother” the lice. The downside of this method is that the Vaseline does not shampoo out of the hair easily — in fact, it usually takes a week or so to get it all out. The upside is that it is not toxic, and from all reports, it seems to work. Washing the hair with dishwashing liquid, which has a degreasing agent in it, may help. I’ve smothered my own hair in mayonnaise (loved the smell), and it came out easily with dishwashing liquid.

To date, the jury is still out about whether or not these alternative treatments are effective. One research scientist has published several articles stating that Vaseline, mayonnaise, and other oil-based treatments cause the lice to go into a dormant state where they are inactive, but not dead. These dormant lice can later “revive” if they are not removed from the hair shaft. It’s important, when trying this method, to brush out any remaining lice to prevent reinfestation after the Vaseline (or mayo) is washed off.

The Packard Children’s Health Services Pediatric Hotline at Stanford is hailing another popular treatment. It uses regular shampoo and three ingredients that can be found at most health-food stores:

Shampoo 3 tbsp olive oil. 1 tsp tea tree oil. 1 tsp rosemary or eucalyptus oil.

Add the oils to a small amount of shampoo and mix well. Work into hair and leave on for half an hour with a tight-fitting shower cap. This mixture has a strong smell. The fumes may burn the eyes, so don’t lean forward. Wash hair two or three times to get the oil out. Repeat the procedure if necessary.

I’m hearing positive reports about this nontoxic treatment, though to my knowledge, no medical studies have been conducted to establish the efficacy or possible side effects of this treatment.

Meanwhile, several other natural compounds are being studied as possible treatments for head lice. Recently, a group of scientists in Argentina published a study looking at treating head lice with the fruit of the “paraiso” tree (Melia azedarach L.). This is a tree that grows easily all over Argentina, also known as “chinaberry tree,” “Indian lilac,” or “white cedar.” They found that both the extract and the oil of this fruit were able to kill adult head lice and some of the nits (Carpinella et al. Journal of the American Academy of Dermatology, 56(2) 2007).

One of our readers suggested using a hot blow-dryer for 15 minutes, morning and evening, in conjunction with thorough nit combing. The heat helps to kill the nits and adult lice, but the combing is essential to the process. This type of treatment should not be combined with the over-the-counter chemical treatments such as Rid and Nix since those chemicals are deactivated by the heat of the blow-dryer. . I’ve had great success combining the blow-dryer with an application of Cetaphil, though. You can read about that treatment here.

As a last resort for extra resistant lice, the Red Book 2000 mentions two prescription medications creams — Lindane and Malathion. To me these cures are worse than the disease — both for those being treated and for the environment. In fact, these creams are thought to be so dangerous in our water supply that the state of California banned the use of lindane to treat lice or scabies.

There are also several prescription oral medications currently being looked at as possible treatments. In the May 1999 issue of Infectious Diseases in Children, Septra (trimethoprim-sulfamethoxazole) is mentioned as a possible treatment for lice. The regimen is twice a day for three days with re-treatment after 7 days. There is some controversy as to whether or not it works. According to the article, it works by changing the bacteria in the gut of the louse, preventing the absorbance of vitamins. The lice then produce infertile eggs and die of malabsorption.

The Key to Success

Whatever treatment you choose, removing lice from the environment is critical to breaking the cycle.

Cleaning Method No. 1

  • After the head is treated, wear a tight-fitting shower cap or bathing cap to prevent re-infestation during the cleaning process.
  • Every surface in your home and car(s) that has touched a head, or has touched an object that has touched a head, must be deloused! All clothes need to be washed in hot water and dried in a hot drier. Even clean clothes that have been hanging in a closet might need to be washed — if a person with lice wears a sweater, then takes it off and puts it back in the closet, any piece of fabric that it touches could become a new home for lice!
  • Wash all bed clothing, including bedspreads, pillows, mattress covers — anything fabric. Dry-cleaning and ironing with a hot iron also kills lice and nits.
  • Clothing and bed coverings that cannot be safely washed in hot water can be double bagged in black plastic bags, sealed tightly, and put away for three days. At the end of that time, wash the clothing according to normal washing instructions.
  • Combs and brushes should be soaked in rubbing alcohol or Lysol for one hour, followed by washing in soapy water.
  • Thoroughly vacuum all carpets — even under the beds! Steam cleaning is even better. Using a high-powered vacuum (not a battery-operated hand-held version), thoroughly vacuum all upholstered furniture. Or better yet, have all upholstered furniture professionally cleaned.
  • Spray and powder forms of lice medicines can be used on carpets, floors, and upholstery. I personally prefer not to use these pesticides unless it is impossible to do a thorough cleaning. If you do need to use one of these products, be sure that your children are not present when you use it, and that you thoroughly air out the space before allowing your children to return.
  • Before you take that lovely shower cap off, be sure to take off all the clothes you’ve been wearing during this process. Put on freshly hot-water laundered clothes, and put your work clothes in the wash.
  • If you do not have access to a washer and dryer in your home, work in teams. Someone who has not been treated yet can put all the loads of laundry into the washers at a public laundry facility. Meanwhile, a second person can be treated, and then go to the laundry and take over. You want to avoid unlaundered clothes if you have been treated (unless you are wearing a shower or bathing cap), and you want to avoid handling clean clothes if you haven’t been treated.

Cleaning Method No. 2 — The Real Alternative

  • This great suggestion came from my friend Dr. Donnica, formerly of NBC’s Later Today show. Instead of cleaning every inch of the house, just lock your house up tight and go on vacation. Get rid of the lice on your heads, and then get out of town. I like this idea. Lice die after 55 hours without a human host. If you can afford to be gone for at least three days, you will return to a lice-free environment.

Returning to School

  • After everyone in the community has completed Day One treatment, it is safe to return to school. Every child, teacher, and staff member should be inspected for lice prior to re-entry. This will make coming back to school the first day after the big cleanup a real zoo. Consider making it into a party! Have a few parents meet early and inspect each other’s heads. Then they can break up into stations in the school parking lot, playground, or some other convenient location that everyone must pass before going into any of the buildings. As each person is inspected, give him or her a sticker — “The Great Lice Adventure!”
  • If a child does not pass, have a plan. Parents cannot be allowed to just drop off their kids on that day. If the child doesn’t pass, the parent must have a provision for alternative child-care (this will be a real incentive to comply with the plan). In addition, have prepared instructions to give to any parents who may need to do all that work over again.

Days Two Through 13

  • Shampoo daily and follow with careful nit-combing. I like using tea tree oil shampoo for this purpose (this is not full-strength tea tree oil, but the shampoo that contains tea tree oil.) Found in health-food stores, this shampoo is reported to prevent re-infestation with lice, but studies have not been done to determine its efficacy.

Day 14

  • Repeat your original treatment choice in order to catch any lice that might have hatched since the first application. Do one last, thorough nit-combing.

Beyond Day 14

  • Continue scalp inspections until the lice have left the community — at least for the time being.

Going back to school to face another year of lice must be very discouraging. Remember that you are part of a community. Blaming others doesn’t help anything; it is important for everyone to work together. By staying positive, the whole process can actually help bring a school together! I know my own children have fond memories of The Great Lice Adventure — now that it’s over!

Pediculosis, Head lice

Head Lice

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Head lice are tiny wingless insects. They live among human hairs and feed on blood from the scalp.

Head lice are a common problem, especially for kids. They spread easily from person to person, and sometimes are tough to get rid of. Their bites can make a child’s scalp itchy and irritated, and scratching can lead to infection.

Head lice are annoying, but they’re not dangerous and they don’t spread disease. They’re not a sign of poor hygiene — head lice need blood and they don’t care whether it’s from someone who’s clean or dirty.

It’s best to treat head lice right away to prevent them from spreading.

What Are the Signs & Symptoms of Head Lice?

Even though they’re tiny, you can see head lice. Here’s what to look for:

  • Lice eggs (nits). These look like tiny yellow, tan, or brown dots before they hatch. Lice lay nits on hair shafts close to the scalp, where the temperature is perfect for keeping warm until they hatch. Nits look a bit like dandruff, but aren’t removed by brushing or shaking them off.
    Unless a child has many head lice, it’s more common to see nits in the hair than live lice crawling on the scalp. Lice eggs hatch 1–2 weeks after they’re laid. After hatching, the remaining shell looks white or clear and stays attached to the hair shaft. This is when it’s easiest to spot them, as the hair is growing longer and the egg shell is moving away from the scalp.

  • Adult lice and nymphs (baby lice). Adult lice are no bigger than a sesame seed and are grayish-white or tan. Nymphs are smaller and become adult lice about 1–2 weeks after they hatch. This life cycle repeats itself about every 3 weeks. Most lice feed on blood several times a day, and they can survive up to 2 days off the scalp.
  • Scratching. With lice bites come itching and scratching. This is due to a reaction to the saliva (spit) of lice. But the itching doesn’t always start right away. It depends on how sensitive a child’s skin is to the lice. It might take weeks for kids with lice to start scratching. They may complain, though, of things tickling or moving around on their heads.
  • Small red bumps or sores from scratching. Some kids have mild irritation from scratching, while others may get a bothersome rash. Scratching a lot can lead to a bacterial infection. Watch for swollen lymph nodes (glands) on the back or front of the neck, and red, tender skin that might have crusting and oozing. Doctors can treat a skin infection with an antibiotic.

How Can I Check My Child for Head Lice?

Look for lice and nits on the scalp, behind the ears, and around the nape of the neck. It’s rare for lice to be in eyelashes or eyebrows.

It can be tough to find a nymph or adult louse. Usually, there aren’t many of them and they move fast. Look for nits attached to the hair near the scalp. They can look like dandruff or dirt. To tell them apart, pull on the little speck with your fingers — dandruff and dirt can be removed, but nits stay stuck. A magnifying glass and a bright light can help with your inspection.

The best way to check is by using a fine-tooth comb on wet hair. After applying lots of conditioner, comb the hair out in very small sections, and look for lice or nits on the comb. You can wipe the comb onto a tissue or paper towel where it will be easier to see them.

If your child is itchy and scratching their head but you’re not sure if it’s lice, ask your child’s doctor or the nurse at school or childcare center to take a look.

How Are Head Lice Treated?

The two main ways to treat lice are:

  • medicine
  • removing by hand

Medicine: Medicated shampoos, cream rinses, and lotions are available that kill lice. These may be over-the-counter (OTC) or prescription medicines. If you buy OTC, be sure it’s safe for your child’s age. While some over-the-counter shampoos are safe for kids as young as 2 months, others are safe only for kids 2 years and older.

In some areas, lice have developed resistance to some medicines. This means they no longer work to kill the lice. Ask your doctor or a pharmacist to recommend a medicine known to work in your area. The doctor also can prescribe a medicated shampoo or lotion. For very resistant lice, the doctor might recommend taking medicine by mouth.

Whether the medicine is OTC or prescription, always follow the directions closely. Applying too much can be harmful. Applying too little won’t work.

Removing by hand: Removing lice and nits by hand can finish the job if the medicine did not completely rid your child of lice (no medicine is 100% effective). It is also an option for anyone who doesn’t want to use an insecticide. And it is the only option for children 2 months old or younger, who should not use medicated lice treatment.

To do this, use a fine-tooth comb on wet, conditioned hair every 3–4 days for 3 weeks after the last live louse was seen. Wetting the hair temporarily stops the lice from moving, and the conditioner makes it easier to get a comb through the hair.

There’s no need to buy electronic combs that claim to kill lice or make nits easier to remove. No studies have been done to back up these claims. You also don’t need to buy special vinegar solutions to apply to the scalp before picking nits. Water and conditioner works fine.

Though petroleum jelly, mayonnaise, or olive oil are sometimes used to try to suffocate head lice, these treatments may not work. If medicine doesn’t work and you want to try these methods, talk to your doctor first.

A few important things to NOT do: Don’t use a hairdryer after applying scalp treatments. Some treatments for lice use flammable ingredients and can catch on fire. Don’t use pesticide sprays or hire a pest control company to try to get rid of the lice; these can be harmful. Don’t use essential oils (such as ylang ylang oil or tea tree oil) to treat lice on the scalp. They can cause allergic skin reactions and aren’t approved by the U.S. Food and Drug Administration (FDA). Don’t ever use highly flammable chemicals such as gasoline or kerosene on anyone.

Are Head Lice Contagious?

Head lice spread quickly from person to person, especially in group settings like schools, childcare centers, slumber parties, sports activities, and camps.

They can’t fly or jump, but they have claws that let them crawl and cling to hair. They spread through head-to-head contact, and sharing clothing, bed linens, combs, brushes, and hats.

Pets can’t catch head lice and pass them on to people or the other way around.

Do Kids Have to Stay Home From School?

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. While they are at school, kids should avoid head-to-head contact with other kids. It can help to put long hair up in a bun, braid, or ponytail.

Can We Prevent Head Lice?

To get rid of head lice and their eggs, and to help prevent them from coming back:

  • Wash all bed linens, stuffed animals, and clothing used during the 2 days before treatment (any lice that fell off before that will not be alive). Wash in very hot water (130°F ), then put them in the hot cycle of the dryer for at least 20 minutes.
  • Dry clean items that can’t be washed. Or put them in airtight bags for 2 weeks.
  • Vacuum carpets and any upholstered furniture (in your home or car), and throw away the vacuum cleaner bag.
  • Soak hair-care items like combs, barrettes, hair ties or bands, headbands, and brushes in hot water or throw them away. Tell kids not to share these items.
  • Because lice easily pass from person to person in the same house, check all family members. Treat everyone who has lice so they won’t pass it back and forth.
  • Tell kids to try to avoid head-to-head contact at school (in gym, on the playground, or during sports) and while playing at home with other children.
  • Every 3 or 4 days, check kids who had close contact with a person who has lice. Then, treat any who have lice or nits close to the scalp.

Will They Ever Be Gone?

As many parents know, fighting head lice can be an ongoing battle. There’s no doubt that they can be hard bugs to get rid of.

If you’ve tried everything and your child still has lice, it could be because:

  • some nits were left behind (if you see nits far from the scalp — more than ½ inch (1 cm) — and no live lice, these are probably dead and treatment likely isn’t needed)
  • your child is still around someone who has lice
  • the treatment you’re using isn’t effective

If your child has lice 2 weeks after you started treatment or if your child’s scalp looks infected, call your doctor.

There are professional lice treatment centers that remove lice and nits for a fee. These services are effective but often costly.

Looking Ahead

Remind your child that while having lice can be embarrassing, anyone can get them. Having head lice is not a sign of dirtiness or poor hygiene. The pesky little bugs can be a problem no matter how often kids do — or don’t — wash their hair or bathe.

Dealing with head lice can be frustrating, but be patient. Follow the treatments and prevention tips from your doctor, and soon your family will be lice-free.

Reviewed by: Michelle P. Tellado, MD Date reviewed: September 2019

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