Head Lice FAQ
Head Lice - Frequently Asked Questions
What Are Head Lice and What Do They Do?
A single scalp parasite is called a louse. The louse egg is called a nit, the hatchling is the nymph, and the adults are called lice. The scientific name for this insect parasite, which lives on the head (in the hair), eyelashes, and eyebrows of humans, is Pediculus humanus capitis.
An infestation of them is called pediculosis. The human scalp provides the perfect conditions of temperature and humidity for louse survival. Even more crucial, the louse feeds on human blood several times each day, like a vampire.
Do They Spread Disease?
Surprisingly, these scalp parasites are generally not associated with the spread of diseases. They are not considered to be public health hazards. Pediculosis is an annoying condition. Unfortunately, it continues to have the (untrue) stigma that infested children are dirty or come from dirty homes.
Who Is At The Greatest Risk for Getting Head Lice?
Lice infestations are a worldwide problem. In the U.S., the head louse problem is most common among preschoolers in child care, kids in elementary school, and the family members of these children. Reliable statistics on lice infections are not available, but one estimate is that 6-12 million infestations occur yearly in children between the ages of 3 and 11 years. African-American children are much less likely to be infested than those of other races, due to differences in hair structure.
How Do Head Lice Spread?
These head parasites cannot fly or even hop. They must crawl to get from hair to hair, and from head to head. Direct hair to hair contact with an infested person is the greatest risk for becoming infested with pediculosis. Infection by sharing hats, brushes, combs and other hair care items of an infected person is uncommon.
My Kids and Home Are Extremely Clean. How Did They Get Lice?
Personal hygiene and home cleanliness do not prevent head lice. Your kids got them from a child who was already infested. Hair-to-hair contact is the most common method. This can occur during school and home play, and from close-contact playground activities, sports, camp, sleepovers, etc.
What Is The Life Cycle Of These Scalp Parasites?
Lice eggs are called nits and are laid by the female louse at the base of a hair shaft, near the scalp. These tiny eggs are about the size of a knot in a piece of thread, and may appear white, yellow, or another color. The eggs are glued to the hair shaft and are difficult to remove. They are often mistaken for dandruff, hair spray residue, or other scalp residue. Nits that are within ¼ inch (6 mm) from the scalp are most likely to hatch. Hatching requires 8 to 9 days.
Nymphs are immature lice that hatch from the nit egg. They look like adults, but are smaller. Nymphs bite the scalp several times a day to suck blood for food. They mature into the adult form between 9 and 12 days after hatching.
The adult hair parasite is a six-legged insect about the size of a sesame seed. They are grayish-white or tan. Like nymphs, the adults bite the scalp and feed on human blood to survive, and live about 30 days. They will die in 1-2 days if removed from the head. The adult female can lay approximately 6 nits (eggs) daily.
What Are The Symptoms Of An Infestation?
An infected person may experience a ticklish feeling as the insects move through his hair. Lice bites may cause itching from allergic reaction. These parasites are more active in the dark, so the infested person may have difficulty sleeping. Scratching the louse bites may also cause skin infections.
Do I Have To Report My Child's Infestation To The Health Department?
This is not required by most U.S. health departments. Sharing information about headlice infestations of your children may help schools and friends' parents avoid or limit further outbreaks. Note that your child's school may have a "no-nit" policy that may require that you keep your child home if lice are detected. Such policies can vary by school.
Do Wigs, Weaves, or Hair Pieces Spread Lice? What About Headphones or Helmets?
Generally not. Artificial hair does not have the same temperature and humidity conditions of the scalp required for these insects to live. Lice claws are effective at gripping human hair, not smooth, artificial surfaces like plastic, vinyl, or metal. However, catching them through such things can happen, although unlikely.
Swimming Kills Them, Right?
Wrong. They can survive underwater for a few hours, but prefer to cling tightly to their host's hair. Swimming too soon after applying head lice remedies or medicines may reduce their effectiveness.
This information was summarized from the Centers for Disease Control (CDC) website. It is not meant to be used for self-diagnosis. It is not intended to be a substitute for a consultation with a health care provider. Use at your own risk.
Source: Centers for Disease Control (CDC) - Parasites Home > Lice > Head Lice > General Information