Description of Head Lice

Head lice (pediculosis) are parasitic insects found on human heads.  There are three forms of lice:  nit, nymph and adult.

Nit:  These are head lice eggs.  They are very hard to see and often confused for dandruff or hairspray droplets.  Nits are found firmly attached to the hair shaft.  They are oval and usually yellow or white.  Nits take about one week to hatch.

Nymph:  The nit hatches into a baby louse.  Nymphs mature into adults about seven days after hatching.  In order to live, nymphs must feed on blood.

Adult:  Adult louse is about the size of a sesame seed, and is tan or grayish-white.  Adult lice can live up to 30 days on a person's head.  In order to live, adult lice needs to feed on blood.  If the lice falls off a person, it dies within two days.

Lice are most commonly found on the scalp behind the ears and near the neckline at the back of the neck.  Head lice hold onto hair with hook-like claws found at the end of each of their six legs.  Head lice are rarely found on the body, eyelashes or eyebrows.

Fee Schedule

Related Health Department Web Links

• Assessment

• Childcare Consultations

• School Safety

Related Outside Web Links

• CDC's Health Information Database

• National Pediculosis Association

What services are provided by Health Department professionals for Cowlitz County?

• Services are no longer offered at the Health Department. Please contact your doctor if you have concerns.

Transmission

Most often head lice are spread through head-to-head contact with another person who has lice. Lice can be spread by wearing another person's hat or clothing, by using another person's comb, brush or bedding, or by placing clothing worn by someone who has lice in a shared clothing storage compartment, locker, or a coat room. Pets do not carry lice.

Populations At Risk

Preschool and elementary school children aged 3-10 years, and their families are infested most often. Girls get head lice more often than boys, and women more than men.

Symptoms

Signs of lice infestation include a tickling feeling on the scalp, itching and sores on the head caused by scratching and possible visual evidence of nits or lice. 

Treatment

The Health Department does not recommend using chemical treatments, such as tea tree oil/melaleuca, Nix, Rid, Pronto, A200 or Kwell or Clear. Instead of these toxic chemicals, a nit comb should  be used to remove nits and lice from the hair. The combs of choice are the Licemeister and the Lice Out. 

In addition, many substances, such as olive oil or mayonnaise may immobilize or stun lice. Apply these immobilizers liberally and then comb the substance out the hair. Lice can live without air for 24 hours, so attempting to smother them without combing is not effective. 

You must also treat the household by washing contaminated clothing and bed linens in hot water, or dry cleaning items such as contaminated stuffed animals, hats, comforters, gloves and scarves. Items that cannot be washed nor dry cleaned should be stored in a sealed plastic bag for at least 2 weeks. Pour boiling water over combs and brushes in a sink over a drain for no longer than 2 seconds. Vacuum floors and furniture, and surfaces where people place their heads.

Diagnosis

Diagnosis should be made by a health care provider, school nurse or health department professional.  A visual inspection of the scalp is used for diagnosis.

Prevention 

Check your children's hair weekly or more often for lice or nits. Begin the removal of lice and nits immediately. Do not share combs, brushes, towels, bedding, hats or clothing. Provide separate storage areas for each person's clothing, costumes, and headgear/helmets.  Use disposable shower caps or inexpensive liners when headgear/helmets must be worn by different children. Assign sleeping mats and bedding to only one person and store these separately at school or day care. Wash or dry clean  clothing and bedding; and vacuum floors and upholstered furniture often.

Potential Complications 

None.