Head Lice (Pediculosis)
Head lice are very small, tan-colored insects (less than1/8" long) which live on human heads. They lay their eggs (nits) close to the scalp. The eggs are tiny (about the size of the eye of a small needle) and gray or white in color.
Signs of Head Lice Infection
Although head lice are hard to find, you can see the nits if you look closely. They are most often found along the hairline at the back of the head and neck and behind the ears. Nits should not be confused with an accumulation of hair spray, hair gels or dandruff. Dandruff can be easily flicked off the hair; nits cannot because they are firmly attached to individual hairs.
Who Can Get Head Lice?
Anyone can get head lice. They are not a sign of being dirty. Most people don't know they are infested until they see the nits or lice. One telltale sign of head lice is a persistent itching of the scalp which is sometimes accompanied by infected scratch marks or what appears to be a rash.
How does an Infestation Occur?
Head lice have no wings and do not fly or jump, but they can run through hair quickly. You can "catch" head lice through:
- Direct contact with an infested person;
- Sharing personal items such as combs, brushes, other hair-care items, towels and pillowcases;
- Sharing clothing, headgear (hats, scarves, football and batting helmets, etc.), ribbons and other head coverings
Shared school lockers and unassigned wall hooks for coats have been associated with higher rates of infestation than individual lockers.
Treatment and Control
If you have questions concerning diagnosis and treatment of head lice, call you doctor or the Douglas County Health Department.
The recommended treatment includes using either a prescription or over-the-counter (OTC) medicated (lice-killing) product. Effective head lice treatments include (1) "Nix", a cream rinse product availability OTC which contains permethrin, a synthetic insecticide; (2) many brands of pyrethrin-based shampoo products ("RID", "R&C", "Triple-X", ext.) which are also available OTC; and (3) "Ovide", a prescription drug containing malathion. With all of these products, the lice are usually killed with one treatment; however a second treatment 7 to 10 days later is often necessary to ensure all of the nits are killed. Because there have been reports of treatment failure with OTC products, when re-treating make sure instructions on the product are being carefully followed or talk to your health care provider. Shampoos containing lindane ("Kwell, etc.) are no longer the first choice for head lice treatment because of the risk of neurological toxicity associated with lindane.
Dead nits do not fall off the hair after treatment. Because they are strongly cemented on, they are often difficult to remove. A nit comb or fingernails can be used to remove nits. Nits remaining in the hair after treatment should not be confused with live nits. Head lice lay their eggs very close to the scalp, and they hatch within a week -- before the hair grows more than 1/4 inch. Nits found more than 1/2 an inch down the hair shaft will have already hatched or been killed during the treatment and their removal is not necessary.
Note: The use of brand names is for identification purposes only, not for product endorsement.
Head lice cannot survive off the human body for more than two days. They do not reproduce off the body. They do not live on pets. Any nits that fall off the head will not hatch or reattach. To keep head lice from returning, you should do the following:
- Wash bedding in hot water (above 130 degrees F) and dry in a hot dryer or iron with a hot iron. Wash and dry recently worn clothing (including coats, caps and scarves) in hot temperatures. Clothing or bedding that cannot be washed may be dry cleaned or sealed in a double plastic bag for two weeks.
- Clean all combs, brushes and similar grooming items by: soaking in the medicated shampoo for 10 minutes or soaking in a 2% Lysol solution for one hour.
- Clean floors, carpeting and furniture by thorough vacuuming only. The use of insecticide sprays is not recommended.
When head lice are present in a community, parents are encouraged to check their children's heads for lice on a regular basis throughout the year. Parents should not depend on someone else to check their child's head, this may delay treatment and result in further spread. Remember, if one person in a family, camp or school has head lice, there's a chance others will too.