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Head Lice

Epidemiology & Health Planning
275 East Main Street
Frankfort, KY  40621
502-564-3418 or 3261 

What are head lice?

Head lice are small parasitic insects found on the heads of people. Head lice (pediculus capitis) is very common in preschool and elementary-age children. Head lice derive nutrients by biting and eating blood several times each day, and cannot survive for more than a day or so at room temperature without ready access to a blood meal.
There are three forms of lice:
Nits: They are head lice eggs that are attached to the hair shaft. They are difficult to see and are white or yellow. They can be mistaken for dandruff. Nits take about 1 week to hatch.
Nymph: The nymph is a baby louse and it is much smaller than an adult louse. The nymph state lasts about 7 days.
Adult: The adult louse is tan to grayish-white and has 6 legs. It is the size of a sesame seed. An adult louse can live 30 days on a person’s head.

Adult female (left) and adult male
 head lice.

How You Get Head Lice

By physical contact with a person that has head lice (head to head, sharing hats, clothing, combs, brushes or towels.
Head lice do not jump from one person to another.
By lying on a bed, couch, pillow, carpet, or stuffed animal that has been used by an infested person.
The Symptoms of Head Lice Infestation


Tickling feeling of something moving in the hair.
Sores can develop from scratching the scalp.
The louse’s saliva and feces may sensitize people to their bites, thereby exacerbating the irritation and increasing the chance of secondary infection from excessive scratching.
How Head Lice Infestation Is Diagnosed

Observation of nits, nymphs, or adult lice on the head of an individual.
If nits are observed ¼ inch from the scalp, the infestation is probably an old one and does not need treating.

How To Treat Head Lice

The drug of choice is permethrin 1%(e.g., Nix).
Pyrethrin (Rid) is used if there appears to be a treatment failure with permethrin.
Other medications are available by prescription.

How To Prevent Infestation of Head Lice

Do not share hats, combs or brushes.
Avoid head to head contact with infected people.
Clarification of Head Lice Myths

Head lice are not known to transmit infectious agents from person to person
Shaving the head bald or cutting the hair short does not prevent head lice.
Hair soaps, bleaches and does do not eliminate head lice.
Pets do not give people head lice.
You can not suffocate the head lice with oils or gels.
Heat from a hair dryer will not kill head lice.
Do not apply any application to the head to repel lice. It will not work.
Do not apply caustic agents to the head to kill lice. They may be harmful to your health.



See Also...
  National Association
National Head Lice Association

Harvard School of Public Health

Last Updated 2/18/2005