What are lice?
Lice are tiny insects that can infest the skin anywhere on the body, causing intense itching. While highly contagious, lice can not jump or fly; they are spread from person to person by close body contact, shared clothing, and items like hats and hairbrushes.
There are three types of human lice:
Facts about lice
- Head lice are seen most commonly in school-aged children and those in child care centers.
- The main manifestation is intense itching of the scalp.
- Live lice can be seen on the hair, behind the ears, and on the neck. The eggs or nits can be found tightly adherent to the hair shaft, closest to the scalp.
Body lice are usually seen in people with poor hygiene and are rare in children.
Unlike head lice, body lice lives on the clothing or bedding; hence improved hygiene and washing clothes will usually eliminate body lice.
Body lice cause severe nighttime itching.
Pubic lice are very contagious and can be transmitted through sexual contact or by contaminated items, such as towels and clothes.
Pubic lice can affect the pubic hair, but can also cause infections of the hair on the chest, abdomen, thighs, and eyebrows.
Itching of the affected area is a common symptom of pubic lice.
How are lice diagnosed?
The eggs are easily visible to the naked eye and appear as small white spots that are cemented to the hair shaft. However it is important to find the adult lice to confirm active infestation and/or treatment failure. Pubic lice leave small brown spots on the parts of clothing that come in contact with the genitals or anus.
Treatment for lice
Treatment for lice is recommended and there are several products available over the counter as well as by prescription.
- Application of a medicated cream rinse or shampoo, known as permethrin (Nix) or pyrethrins (RID), are available over the counter, least expensive and usually effective treatment although resistance can occur. Specific instructions as well as age considerations, need to be followed to minimize reinfection and treatment failures.
- Lindane - Due to toxicity, this product is no longer recommended as first line treatment for lice and should be avoided in patients with skin disorders or open sores.
- Examples of medicated cream rinses or shampoos available by prescription include:
- Malathion - While safe and effective, this product is highly flammable and malodorous and is contraindicated in children under 2 years of age.
- Ivermectin - Topical Ivermectin is highly effective but can be costly and therefore prohibitive for some patients.
- Nits need to be removed from the hair with a fine-tooth comb.
- Combs and brushes should be soaked in hot water with the shampoo for a period of at least 15 minutes.
- Children can return to school or day care the day following their first treatment for head lice. Presence of nits only should not be a reason to exclude the children from school.
- Check all other household members closely to see if anyone else needs to be treated.
- Wash all bedding and clothing in hot water (130° F or 54° C), or seal items that cannot be washed in a plastic bag for two weeks.
Reviewed by Chun H. Yin, MD, FAAP