Head Lice - Fact Sheet
What are head lice?
Head lice are blood sucking parasites. They are approximately the size of a sesame seed, 1-2 mm. They do not have wings and, therefore, cannot fly. They also do not jump. They do, however, move quickly. The eggs of the louse, which are called "nits", are teardrop shaped and approximately half the size of the adult louse. The nits are attached to the hair shaft with a waterproof, cement-like substance from the adult female. Thus, nits cannot be simply washed or brushed out of the hair.
Who can get head lice?
Anyone who comes in contact with louse infested items can get head lice. Some people think lice become established on persons who are unclean. This is not true. Frequent bathing will neither prevent head lice nor eliminate an infestation once it has become established.
How are head lice spread?
Head lice are usually transmitted through close personal contact with another infested individual or through use of common combs, brushes, and other grooming aids; through sharing hats, caps, coats; or through co-mingling of these items at the homes of friends, at school, at church, or other public places.
What are the symptoms of infestation with head lice?
The major symptom of head lice is itching, which is due to the presence of salivary fluid produced by the insect as it feeds.
How do you eliminate head lice?
Treatment is directed at the infested individual and his personal articles (e.g., caps, combs, brushes, towels, and bedding). Fumigation or use of insecticides in the home, school, or school buses is not recommended.
A. Individual Treatment:
Individual treatment usually requires using an over-the-counter (OTC) or prescription medication and a nit (head lice egg) comb.
WARNING: Do not use a creme rinse or combination shampoo/conditioner before using lice medicine. Do not re-wash hair for 1-2 days after treatment.
Follow these treatment steps:
Before application of the OTC or prescription treatment, remove all clothing from the waist up.
Apply the lice medicine according to label instructions. If your child has hair longer than shoulder length, you may need to use two bottles. It is important to pay special attention to instructions on the bottle regarding how long the medication should be left on and whether rinsing the hair is recommended after treatment.
After treatment, have the infested person put on clean clothing.
Nit combs, often found in lice medicine packages, should be used to comb nits and lice from the hair shaft. Many flea combs made for cats and dogs are also effective.
After treatment, check the hair every 2-3 days, and comb with a nit comb to remove nits and lice as necessary. Continue to check for 2-3 weeks until you are sure all lice and nits are gone.
If an OTC medicine was used, retreat in 7-10 days. If the prescription drug malathion was used, retreat in 7-10 days ONLY if crawling bugs are found.
B. Decontamination of Personal Articles and Environment:
Treat the household: If head lice fall off of a person and cannot feed, they will not survive very long. It is not necessary to spend a lot of time or money on housecleaning activities. You can help avoid re-infestation by lice that may have recently fallen off the hair or crawled onto clothing or furniture by following these steps.
To kill lice and nits, all washable clothing and bed linens that the infested person wore or used during the 2 days before treatment should be machine washed in hot water (130°F). After the hot wash, the laundry should be dried at high heat for at least 20 minutes.
For clothing that is not washable, have it dry cleaned. (e.g., coats, hats, scarves).
All clothing, stuffed animals, comforters, etc. that cannot be washed or dry cleaned can be stored for 2 weeks in a plastic bag that is sealed with tape.
Combs and brushes can be soaked for 1 hour in rubbing alcohol, Lysol*, or wash with soap and hot (130°F) water.
Vacuum the floor and furniture. There is a small risk of getting re-infested from a louse that has fallen onto the carpet or onto a sofa. Vacuum the places where the infested person usually sits or lays, spending a lot of time on this is not necessary. Do not use fumigant sprays; they can be toxic if inhaled or absorbed through the skin.
C. Prevent Reinfestation:
The most common way to spread lice is through direct head-to-head contact. It is less likely for lice to spread by crawling onto clothing or belongings. To control head lice outbreaks in a community, school or camp setting, children can be taught to avoid activities that are likely to spread lice.
- Avoid head-to-head contact during play at school and at home (on a playground, sleep over party, camp, sports outing).
- Do not share any items that may have had contact with someone elses head (e.g., hats, scarves, hair ribbons, coats, sports uniforms).
- Do not share combs, brushes, or towels.
- If you are aware that someone has a lice infestation, do not lie on the beds, couches, pillows, carpets, or stuffed animals that the infested person may have had contact with.
* Lysol is a registered trademark. The mention of this product does not constitute an endorsement by the Connecticut Department of Public Health.
This fact sheet is for informational purposes only. It should not be used for self-diagnosis or as a substitute for consultation with a health care provider. If you think that you may have this infection, or have questions about the disease described above, you should consult your health care provider.
For additional information on this disease, visit the Centers or Disease Control and Prevention website.
To contact the Epidemiology and Emerging Infections Program, please call 860-509-7994.