Head lice are tiny insects that feed on blood from the human scalp and lay their eggs on hair. Head lice are very common, particularly in children. There is no connection between head lice and the length of someone's hair or the cleanliness of the hair, body, or home or school environment.
The medical name for head lice is Pediculosis humanus capitis.
The most common way to get head lice is head-to-head contact with a person who already has head lice. Head-to-head contact is common at home and school, in sports, on the playground, and at sleepovers and at camp.
It is very uncommon, but possible, to get head lice from clothing or belongings containing lice or nits that have crawled or fallen from a person with head lice. Examples include:
Head lice cannot hop or jump, and they do not have wings, so they cannot fly.
You cannot catch head lice from dogs, cats, and other pets - head lice cannot survive on them.
Head lice are not known to transmit any disease and therefore are not considered a health hazard. However, people with head lice sometimes develop bacterial infections from scratching the skin or scalp.
The most common sign of head lice is itching, but most people do not develop itching until after head lice have been present for several weeks. Other possible symptoms are a tickling feeling of something moving in the hair and sores on the head caused by scratching. Irritability and difficulty sleeping may also be signs, since head lice are most active in the dark.
It is usually easiest to find head lice on the scalp behind the ears, and near the neckline at the back of the neck. Occasionally, lice fall onto a person's eyebrows and eyelashes.
There are three stages in the lifecycle of head lice, and each stage looks different.
Adult lice avoid light and can move quickly. They may be hard to see on the scalp. Parents may use a louse or nit comb to find eggs/nits.
In the United States, head lice are common among preschool children attending child care centers, elementary school children, and household members of children with head lice.
Many head lice medications are available over-the-counter. Your health care provider may prescribe others.
To treat for head lice using a shampoo, conditioner, or lice-killing hair lotion, follow these steps:
Follow the instructions packaged with a lice comb, if you use one as the only lice treatment. Metal combs are often better at removing lice than plastic combs. The scalp of the person with lice may need daily 30 minute to 1 hour combing sessions for several days in order to remove all crawling lice and any nits/eggs that are ¼ inch or closer to the scalp.
S.C. DHEC does not recommend for or against use of herbal or botanical treatments for head lice. School districts may opt to allow these treatments, and may opt to identify which products are acceptable for treatment in order for a child to return to school.
Home remedies, such as oils, shortening, vinegar, etc., do not consistently clear head lice infestations. These are not recommended.
Kerosene and gasoline should NEVER be used to treat head lice.
According to the U.S. Centers for Disease Control and Prevention (CDC), chemical treatments for head lice are generally safe and effective when used correctly. Some treatments may cause an itching or a mild burning sensation caused by inflammation of the skin on the scalp. Most products used to treat head lice are pesticides that can be absorbed through the skin. Use any lice killing medicine only as directed.
Check with your health care provider if you have used a lice-killing product 2-3 times, following label directions, and there are still live crawling lice visible. Your health care provider may recommend a different treatment.
Take these steps to help prevent the spread of head lice to other members of your household:
Children will need to be treated for head lice if there are live, crawling lice seen on the scalp, or if there are nits/eggs that appear to be ¼ inch from the scalp. Children and students may remain at school until the end of the day. They should avoid activities that include head-to-head contact. Childcare centers may opt to send children home right away when lice are found, if head-to-head contact cannot be avoided in the classroom/center.
Children may return to school or childcare after one treatment with an over-the-counter or prescription lice-killing product. The school may make recommendations for products. The school or center may also allow children to return after crawling lice-nits have been removed from the hair by combing or heat treatment methods.
The child cannot return to school if there are any live, crawling lice seen on the scalp. Check the child's scalp 7-10 days after first treatment. If there are any live crawling lice, the treatment must be repeated in order to return to school.