Head lice are tiny insects that feed on blood from the human scalp. Head lice most often affect children. The insects usually spread through direct transfer from the hair of one person to the hair of another.
See a health care provider before you begin treatment if you suspect that you or your child has head lice. Your or your child's health care provider can confirm that head lice are present. Studies show that many children have been treated for head lice with nonprescription medications or home remedies when they didn't have lice.
A head louse is a tan or grayish insect about the size of a strawberry seed. It feeds on human blood from the scalp. The female louse produces a sticky substance that firmly attaches each egg to the base of a hair shaft less than 1/4 inch (5 millimeters) from the scalp.
Head lice crawl, but they can't jump or fly. Head lice often spread from one person to another by direct head-to-head contact, often within a family or among children who have close contact at school or play.
Head lice may also spread when items of clothing are stored together. For example, hats or scarves hung on the same hook or stored in the same school locker could serve as vehicles for spreading lice.
Head lice are spread primarily by direct head-to-head contact. So the risk of spreading head lice is greatest among children who play or go to school together. In the United States, cases of head lice most often occur in children in preschool through elementary school.
Head lice are a common problem, especially among school-aged children and their families. The lice can attach to the hair of anyone's head. It doesn't matter if the hair is clean or dirty. Head lice are also found worldwide in all different places, such as in homes or schools or the country or city. It doesn't matter how clean, dirty, rich or poor the place or person is.
Though head lice may be a nuisance, they don't cause serious illness or carry any diseases. Head lice can be treated at home, but it's important to check with the doctor first. (See "Head Lice Medicines," below).
Head lice are crawling insects. They cannot jump, hop, or fly. The main way that head lice spread is from close, prolonged head-to-head contact. There is a very small chance that head lice will spread by sharing items such as combs, brushes, hats and sports helmets.
Itching on the areas where head lice are present is the most common symptom. However, it may take up to 4 to 6 weeks after lice get on the scalp before the scalp becomes sensitive to the lice saliva and begins to itch. Most of the itching happens behind the ears or at the back of the neck. Also, itching caused by head lice can last for weeks, even after the lice are gone.
The comb-out method can be used to help check for nits and head lice or to help remove nits and head lice after head lice treatment. However, the comb-out method usually doesn't work on its own to get rid of head lice.
Check with your child's doctor before beginning any head lice treatment. The most effective way to treat head lice is with head lice medicine. After each treatment, using the comb-out method every 2 to 3 days for 2 to 3 weeks may help remove the nits and eggs.
Always rinse the medicine off over a sink and not during a shower or bath, so the medicine doesn't run off the head onto other areas of skin. Place your child's head over a sink and rinse the medicine off with warm water (not hot water).
You may want to wash your child's clothes, towels, hats, and bed linens in hot water and dry on high heat if they were used within 2 days before head lice were found and treated. You do not need to throw these items away. Items that cannot be washed may be sealed in a plastic bag for 2 weeks or dry-cleaned..
Some schools have "no-nit" policies stating that students who still have nits in their hair cannot return to school. The American Academy of Pediatrics and National Association of School Nurses discourage such policies and believe a child should not miss or be excluded from school because of head lice.
Head lice don't put your child at risk for any serious health problems. Products should be used only if those products are safe. If your child has head lice, work quickly but safely to treat your child to prevent the head lice from spreading.
The head louse, or Pediculus humanus capitis, is a parasitic insect that can be found on the head, eyebrows, and eyelashes of people. Head lice feed on human blood several times a day and live close to the human scalp. Head lice are not known to spread disease.
Head lice are found worldwide. In the United States, infestation with head lice is most common among pre-school children attending child care, elementary schoolchildren, 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 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.
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 even after the nymphs hatch and empty casings remain.
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).
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 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 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 -inch from the scalp, the infestation is probably old and no longer active and does not need to be treated.
Most health departments do not require reporting of head lice infestation. However, it may be beneficial for the sake of others to share information with school nurses, parents of classmates, and others about contact with head lice.
No. CDC is not a regulatory agency. School head lice policies often are determined by local school boards. Local health departments may have guidelines that address school head lice policies; check with your local and state health departments to see if they have such recommendations.
Head lice should not be considered as a medical or public health hazard. Head lice are not known to spread disease. Head lice can be an annoyance because their presence may cause itching and loss of sleep. Sometimes the itching can lead to excessive scratching that can sometimes increase the chance of a secondary skin infection.
Head lice are spread most commonly by direct contact with the hair of an infested person. Spread by contact with inanimate objects and personal belongings may occur but is very uncommon. Head lice feet are specially adapted for holding onto human hair. Head lice would have difficulty attaching firmly to smooth or slippery surfaces like plastic, metal, polished synthetic leathers, and other similar materials.
Head lice and their eggs (nits) soon perish if separated from their human host. Adult head lice can live only a day or so off the human head without blood for feeding. Nymphs (young head lice) can live only for several hours without feeding on a human. Nits (head lice eggs) generally die within a week away from their human host and cannot hatch at a temperature lower than that close to the human scalp. For these reasons, the risk of transmission of head lice from a wig or other hairpiece is extremely small, particularly if the wig or hairpiece has not been worn within the preceding 48 hours by someone who is actively infested with live head lice.
Data show that head lice can survive under water for several hours but are unlikely to be spread by the water in a swimming pool. Head lice have been seen to hold tightly to human hair and not let go when submerged under water. Chlorine levels found in pool water do not kill head lice.
There are several products that you can buy at your local drug or grocery store to get rid of head lice and their nits. These are available without a prescription. Dermatologists offer the following tips for using these products:
Apply the product to the head of a fully dressed person, and rinse the product out with a spray hose or running water from a sink. These products are not meant for use while taking a shower or bath. You want to limit the amount of skin that the product touches. 041b061a72