Nits (the eggs of the head louse) are small browinish, oval-shaped eggs that are "to the side of a hair shaft glued" at an angle.

Nits must be laid by live lice. You cannot "catch nits."

Once laid, it takes 7-10 days for a nit to hatch, and another 7-10 days for the female to mature and begin laying her own eggs.

Head lice are clear in color when hatched, then quickly develop a reddish-brown color after feeding.

Head lice are about the size of sesame seeds.

Head lice have six legs equipped with claws to grasp the hair.

Head lice are crawling insects. They cannot hop, jump, or fly.

Head lice do not thrive on pets.

Head lice are small, wingless insects which feed on human blood. They need human blood in order to survive.

Head lice live for approximately 30 days on a host and a female louse may lay up to 100 nits (eggs).

Head lice off of their human hosts will starve. The NPA suggests that, in most cases, a head louse will not survive for more than 24 hours off of its human host.

Home Cleaning Procedures:

Head Lice are parasites that require human blood to survive.  They can only live for 24-48 hours away from a human host.  Vaccuming is the safest and best way to clean up lice from your floors and couches.  Pesticide sprays are not recommended.  

Couch: Vaccume and cover with a sheet or blanket for 3 days

Floors: Vaccume or sweep

Clothes:  Put in dryer for 30-60 minutes on high heat.  

Bedding, Stuffed Animals, Backpacks:  Put in drier for 30-60 minutes or put them away and do not use for 3 days.

Combs and Hair Accessories: Put in bucket for water and add small amout of bleach for 4+ hours or put in plastic bag and freeze for 4+hours

Car Seats: Vaccume or cover with cloth for 3 days

Note: The safest method to clean something is to simply separate from it for 3 days. (either in a plasic bag or put in an unused closet. ) 

Head Lice Pictures:


Basics of Lice 
From the National Pediculosis Association
What are head lice?

The head louse, or Pediculus humanus capitis (peh-DICK-you-lus HUE-man-us CAP-ih-TUS), is a parasitic insect that can be found on the head, eyebrows, and eyelashes of people. Head lice feed on human blood several time a day and live close to the human scalp. Head lice are not known to spread disease.

Who is at risk for getting head lice?

Head lice are found worldwide. In the United States, infestation with head lice is most common among preschool children attending child care, elementary school children, and the household members of infested children. Although reliable data on how many people in the United States get head lice each year are not available, an estimated 6 million to 12 million infestations occur each year in the United States among children 3 to 11 years of age. In the United States, infestation with head lice is much less common among African-Americans than among persons of other races, possibly because the claws of the of the head louse found most frequently in the United States are better adapted for grasping the shape and width of the hair shaft of other races.

Head lice move by crawling; they cannot hop or fly. Head lice are spread by direct contact with the hair of an infested person. Anyone who comes in head-to-head contact with someone who already has head lice is at greatest risk. Spread by contact with clothing (such as hats, scarves, coats) or other personal items (such as combs, brushes, or towels) used by an infested person is uncommon. Personal hygiene or cleanliness in the home or school has nothing to do with getting head lice.

What do head lice look like?

Head lice have three forms: the egg (also called a nit), the nymph, and the adult.
Size of head lice compared to a penny

Egg/Nit: Nits are lice eggs laid by the adult female head louse at the base of the hair shaft nearest the scalp. Nits are firmly attached to the hair shaft and are oval-shaped and very small (about the size of a knot in thread) and hard to see. Nits often appear yellow or white although live nits sometimes appear to be the same color as the hair of the infested person. Nits are often confused with dandruff, scabs, or hair spray droplets. Head lice nits usually take about 8-9 days to hatch. Eggs that are likely to hatch are usually located no more than ¼ inch (or 1 centimeter) from the base of the hair shaft.

Head lice nymph

Nymph form

Nymph: A nymph is an immature louse that hatches from the nit. A nymph looks like an adult head louse, but is smaller. To live, a nymph must feed on blood. Nymphs mature into adults about 9-12 days after hatching from the nit.
Adult head louse

Adult louse.
Adult: The fully grown and developed adult louse is about the size of a sesame seed, has six legs, and is tan to grayish-white in color. Adult head lice may look darker in persons with dark hair than in persons with light hair. To survive, adult head lice must feed on blood. An adult head louse can live about 30 days on a person’s head but will die within one or two days if it falls off a person. Adult female head lice are usually larger than males and can lay about six eggs each day.

Where are head lice most commonly found?
Image of an adult head louse's claws

Adult louse claws. 

Head lice and head lice nits are found almost exclusively on the scalp, particularly around and behind the ears and near the neckline at the back of the head. Head lice or head lice nits sometimes are found on the eyelashes or eyebrows but this is uncommon. Head lice hold tightly to hair with hook-like claws at the end of each of their six legs; head lice nits are cemented firmly to the hair shaft and can be difficult to remove.

What are the signs and symptoms of head lice infestation?

    * Tickling feeling of something moving in the hair.
    * Itching, caused by an allergic reaction to the bites of the head louse.
    * Irritability and difficulty sleeping; head lice are most active in the dark..
    * Sores on the head caused by scratching. These sores can sometimes become infected with bacteria found on the person's skin.

How did my child get head lice?

Head-to-head contact with an already infested person is the most common way to get head lice. Head-to-head contact is common during play at school, at home, and elsewhere (sports activities, playground, slumber parties, camp).

Uncommonly, head lice may be spread by sharing clothing or belongings onto which lice or nits may have crawled or fallen. Examples include:

    * sharing clothing (hats, scarves, coats, sports uniforms) or articles (hair ribbons, barrettes, combs, brushes, towels, stuffed animals) recently worn or used by an infested person;
    * or lying on a bed, couch, pillow, or carpet that has recently been in contact with an infested person. The risk of getting an infestation by a louse or nit that has fallen onto a carpet or furniture is very small.

Dogs, cats, and other pets do not play a role in the spread of human lice.

How is head lice infestation diagnosed?

The diagnosis of a head lice infestation is best made by finding a live nymph or adult louse on the scalp or hair of a person. Because nymphs and adult lice are very small, move quickly, and avoid light, they can be difficult to find. Use of a magnifying lens and a fine-toothed comb may be helpful to find live lice. If crawling lice are not seen, finding nits firmly attached within a 1/4 inch of base of the hair shafts strongly suggests, but does not confirm, that a person is infested and should be treated. Nits that are attached more than 1/4 inch from the base of the hair shaft are almost always dead or already hatched. Nits are often confused with other things found in the hair such as dandruff, hair spray droplets, and dirt particles. If no live nymphs or adult lice are seen, and the only nits found are more than ¼-inch from the scalp, the infestation is probably old and no longer active and does not need to be treated.

When to contact a doctor?

Call your health care provider if symptoms continue after home treatment, or if you develop areas of red, tender skin, which could mean a possible infection.
Head Lice Fact Sheet
From Center for Disease Control and Prevention (CDC)

Nit (egg)

Nymphs are premature lice.  Nymphs are translucent tan in color and can be difficult to see with the naked eye.  
Picture of adult head lice 
Nit Casting 
(non-viable, not a nit)

The clear/white sacks pictures to the left are nit castings.  They are hatched, non-viable eggs.  
Nit (viable lice egg)
You are here: SFGate Home→Collections→Public Health

    * Public Health

OAKLAND / Schools liberalize lice rules / End of 'no-nits' era -- infested kids can now stay in class
January 23, 2007|By Jill Tucker, Chronicle Staff Writer

Nora Cody was in the middle of a work meeting when she got the dreaded call from her daughter's school.

Head lice, the Chabot Elementary secretary said on the other end of the phone. Come pick her up.

That was last year. This year, no Oakland Unified School District parent will get that call.

Under new guidelines, Oakland children with lice or nits will be allowed to stay in class -- a policy that may be a first in the Bay Area.
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Oakland officials cited schools in western Australia as their model, saying the policy encourages treatment and is justified.

"There are no serious health consequences or risks of students having head lice," said Joan Edelstein, the district's health services coordinator. "We don't want students to be missing five to 10 days of schools when they pose no risk of harm to themselves or anyone else."

The American Academy of Pediatrics and the National Association of School Nurses support the policy. They say lice are often misdiagnosed by untrained school staff. In addition, children with lice have often had it for weeks or a month before detection, according to the national organizations.

Yet some parents at Chabot are scratching their heads over the policy, said Principal Jon Mayer.

At least half of the school's 23 classrooms have had cases of lice so far this year, compared to just a few from all of last year, Mayer said.

"We're not saying it's a result of the policy, but for some reason it's worse this year," he said. "We're just doing the best we can to educate parents more thoroughly on the issue."

On the plus side, children aren't missing school, Mayer added.

Edelstein said she was unaware of any lice infestations at district schools, including Chabot, which is located in the middle- to upper-class Rockridge district.

In the meantime, Chabot kindergarten parent Grecia Bloom said parents are washing all the kindergarteners' nap blankets and pillows to try to eradicate the problem. For a week, her child's classmates rested at their desks, heads in their arms, rather than on the floor with pillows and blankets.

"I thought it was an ancient problem," Bloom said, adding that she assumed it only affected developing countries. "Yet it's here and it's annoying."

In fact, lice are everywhere.

"You should on average expect about 1 percent of kids in kindergarten through fourth-grade levels to be actively infested with head lice at any given time at any school, in any community in North America," said Richard Pollack, a public health entomologist at the Harvard School of Public Health.

Lice by most anyone's standards are icky: They attach to human hair and feed on human blood. They also lay eggs on hair, which hatch, latch and repeat.

Perhaps understandably, few districts or schools across the country have a "no exclusion" policy like Oakland's.

Most, including San Francisco, New Haven (Union City) and Pleasanton, send children home when they find nits or lice, a so-called no-nits policy.

That mentality is almost universal, Pollack said. People believe lice spread easily and that they're linked to unsanitary conditions -- myths, he says.

As a result, he said, more public health agencies and organizations are recommending a more liberal approach of allowing nits in class.

The California Department of Health Services, for example, recommends sending children home only when live adult lice are present, a policy Santa Clara Unified follows.

Pollack, however, said he would like more schools to follow Oakland's lead.

Screening at schools is often inaccurate, meaning many students are misdiagnosed with lice or never diagnosed at all anyway, he said.

"I've been pushing for sanity for many, many years," he said, adding that there's more to gain by keeping students in class: Kids keep learning and parents get to stay at work.

In California, it also means Oakland doesn't lose state money only allocated when students are in school, but not when they're out sick -- or home with lice.

Chabot's Cody, who is also the district's wellness coordinator, said that as a parent she's thrilled with the policy, knowing she won't have leave work for lice again.

"Kids go to school with snot running down their face, but nobody sends them home," she said.

Oakland's policy also doesn't bother Chabot parent Jody London.

"Having lice is not a life-threatening situation," she said. "It's just creepy and uncomfortable."

Yet, she can also see the other side.

"I can also see a parent going, 'Oh my God, why did you let a kid with lice in the classroom?' " she said. "It's a very frustrating problem." 

See the article at http://articles.sfgate.com/2007-01-23/bay-area/17229259_1_lice-or-nits-head-lice-school-nurses
Oakland School allowing childen to school with nits
Head lice (Pediculus capitis) are small parasitic insects exquisitely adapted to living mainly on the scalp and neck hairs of their human host. Their six impressive legs are elegantly evolved to grasp hair shafts and provide a striking example of biological specialization. Long associated with people, head lice have been recovered from prehistoric mummies. Head lice are equal opportunity parasites; they do not respect socio-economic class distinctions. Their presence does not connote a lack of hygiene or sanitation practiced by their host. Head lice are mainly acquired by direct head-to-head contact with an infested person's hair, but may infrequently be transferred with shared combs, hats and other hair accessories. They may also remain on bedding or upholstered furniture for a brief period.  In North America and Europe, children are more frequently infested than are adults, and Caucasians more frequently than other ethnic groups. Neither able to fly nor jump, lice are also unlikely to wander far from their preferred habitat. Lice and their eggs are unable to burrow into the scalp. Lice are sometimes referred to as cooties, eggs as nits and infested people as lousy. The infestation by head or body lice is termed pediculiasis, and the associated "disease" pediculosis. Delousing (more properly termed lousing) consists of any method for eliminating an infestation. Chemical treatments directed against lice are pediculicides. Those that kill adult and nymphal lice are sometimes called lousicides;  those that kill the developing embryo within the egg are ovicides. This discussion relates to head lice unless specific mention is made of other types of lice.

Head lice derive nutrient by blood-feeding once or more often each day, and cannot survive for more than a day or so at room temperature without ready access to a person's blood. A nymphal louse hatches from its egg after about 8 days of development, and begins to feed, grow and develop until it attains the adult stage about 9-12 days after hatching. A female louse may deposit more than 100 eggs at a rate of about six eggs each day. Only those eggs deposited by inseminated female lice will hatch. Generally, an infested person has fewer than a dozen active lice on the scalp at any time, but may have hundreds of viable, dead and hatched eggs. With adequate magnification, the developing nymph can be seen within the egg; hatched eggs are nearly transparent (see photos accompanying this site).

Treatment should be considered only when active lice or viable eggs are observed. Itching of the scalp or the perception that something is crawling on the head do not warrant treatment for lice. Without magnification and suitable experience, they may be difficult to correctly distinguish from other material caught in the hair. Amongst presumed "lice" and "nits" submitted by physicians, nurses, teachers and parents, most are simply artifacts such as dandruff, hairspray droplets, scabs, dirt, or other insects (e.g. aphids blown by the wind and caught in the hair).  To confirm the identity of suspected material, save a few lice and louse eggs under clear tape on our specimen submission form, and record the requested information.  Submit the samples to us or to a qualified physician or entomologist to confirm the identity of the offending creatures
What are head lice, and how do they differ from other lice?
From Harvard School of Public Health
Home Cleaning and Lice Pictures
A new report by the American Academy of Pediatrics has revealed that school policies used to control outbreaks of head lice among students are too strict in relation to the contagion threat posed by head lice.

The report called on schools to stop no-nits policies (which require children to be free of nits before returning to school).

"We are trying to take a firmer position against the no-nits policy because it makes no medical sense and was never shown to be effective," said Barbara Frankowski, a pediatrician at Vermont Children's Hospital.

The report also noted that no-nits policies were often used on children who did not actually have lice, and highlighted the fact that most contagion of lice occurs in situations where children are in close physical contact (such as sleepovers and camps) rather than in schools, and pointed out that no-nits policies put children who are forced to stay home at an academic disadvantage.

by RTT Staff Writer
Health News
New Report Urges Review Of School Head Lice Policies

By DAN CHILDS (@DanChildsABC) , ABC News Medical Unit
July 26, 2010

Call it a new battle plan in the war on lice.

The American Academy of Pediatrics released a new set of guidelines in the current issue of "Pediatrics" for the treatment of head lice, the first update in recommendations that the organization has issued since 2002.

The new report is unlikely to end humankind's age-old struggle against the itch-inducing bugs, but it is intended to alert the public to the various ways to solve lice infestations in schools and to inform on the resistance of lice to certain treatments and the new methods of treatment emerging today.

Lice infestation is not life threatening, but the stigma of lice has led parents to attempt dangerous methods of treatment ranging from acetone, bleach and WD-40 to loosen eggs from the hair, to dousing their children's scalps with gasoline. When all else fails, parents have been known to resort to shaving their children's heads -- an effective option for getting rid of lice and their eggs, but traumatic nonetheless.

Infestation's comparatively non-serious nature may be partly to blame for the relative lack of reliable statistics on the extent of the problem. An oft-quoted 1997 report estimated that between 6 and 12 million infestations occur each year, but experts caution the public not to place too much stock in this ballpark range
PHOTO The American Academy of Pediatrics has released a new set of guidelines for the treatment of head lice -- the first update in recommendations that the organization has issued since 2002.
Ian Hooton/Getty Images
A woman combs her daughter's hair with a... View Full Caption
A woman combs her daughter's hair with a nitcomb in this file photo. The American Academy of Pediatrics has released a new set of guidelines for the treatment of head lice -- the first update in recommendations that the organization has issued since 2002. Close

"Many doctors would say [lice infestations in schools are] no problem, since lice usually don't cause any medical problems -- just itching," said Dr. Barbara Frankowski, professor of pediatrics at the University of Vermont in Burlington and one of the authors of the report. "Since it is not reported to health departments, the actual extent of the 'problem' is just a guess."

AAP Suggests Anti-Lice Options

Lice are rapidly evolving resistance to chemicals in many anti-louse shampoos and other remedies, and the new guidelines expand the recommended arsenal against the bugs.

While the 2002 guidelines listed permethrin (commonly known as Nix) as the approved treatment, the new set adds products known as pyrethrins to the lineup, as well as benzyl alcohol, which is to be used only when other methods fail.

"The guidelines provide info on new and traditional approved options," said Dr. Bernard Cohen, director of pediatric dermatology at the Johns Hopkins Medical Institution in Baltimore, Md. "Some off-label [treatments] are also effective, in my opinion, but there are a number of ineffective costly meds and techniques that desperate parents embrace."

The recommendations also strengthen the AAP's stance against school screenings for lice, stating as its first key point, "No healthy child should be excluded from or allowed to miss school time because of head lice. No-nit policies for return to school should be abandoned."

A similar, albeit less strongly worded recommendation was part of the 2002 guidelines, but the practice is still a fixture at some schools.

"Although the Association of School Nurses agreed that a no-nit policy does not make sense over a decade ago, many school still try to enforce the policy," Cohen said.

One thing the new report is unlikely to solve is the stigma that surrounds lice infestation.

"Many parents perceive lice infestation as a sign of poor hygiene or poor parenting, which isn't true," said Dr. Steve Lauer, vice chairman and associate professor at the University of Kansas Medical Center Department of Pediatrics in Kansas City.

"[I] think it is important to understand that lice infestations do not indicate uncleanliness," said Dr. Sara Rizvi, assistant professor of pediatrics at the Baylor College of Medicine in Houston.

These perceptions, pediatricians hope, will soon fall to the wayside as new treatments become available.

"There are numerous treatment options for head lice infestation," said Dr. Amit Deokar, a pediatrician with the University of Kentucky's Division of Adolescent Medicine in Lexington. "Because of various treatment options available these days, the infected person and family members living with them can be treated at the same time ... some of the treatment options are extremely effective."

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