Pediculosis capitis - head lice
Head lice are tiny insects that live on the skin covering the top of your head (scalp). Head lice may also be found in eyebrows and eyelashes.
Lice can be spread by close contact with other people.
Head lice infect hair on the head. Tiny eggs on the hair look like flakes of dandruff. However, instead of flaking off the scalp, they stay in place.
Head lice can live up to 30 days on a human. Their eggs can live for more than 2 weeks.
Head lice spread easily, particularly among school children. Head lice are more common in close, overcrowded living conditions.
You can get head lice if:
Having head lice causes intense itching, but does not lead to serious medical problems. Unlike body lice, head lice never carry or spread diseases.
Having head lice does NOT mean the person has poor hygiene or low social status.
Symptoms of head lice include:
Head lice can be hard to see. You need to look closely. Use disposable gloves and look at the person's head under a bright light. Full sun or the brightest lights in your home during daylight hours work well. A magnifying glass can help.
To look for head lice:
Both children and adults should be treated right away if any lice or eggs are found.
Lotions and shampoos containing 1% permethrin (Nix) often work well. You can buy these medicines at the store without a prescription. If these products do not work, a health care provider can give you a prescription for stronger medicine. Always use the medicines exactly as directed. Using them too often or in the wrong way can cause side effects.
To use the medicine shampoo:
You also need to get rid of the lice eggs (nits) to keep lice from coming back.
To get rid of nits:
When treating lice, wash all clothes and bed linens in hot water with detergent. This also helps prevent head lice from spreading to others during the short period when head lice can survive off the human body.
Ask your provider if people who share bedding or clothes with the person who has head lice need to be treated as well.
Most of the time, lice are killed with the proper treatment. However, lice can come back if you do not get rid of them at the source.
Some people will develop a skin infection from scratching. Antihistamines can help ease itching.
Call your provider if:
Never share hair brushes, combs, hair pieces, hats, bedding, towels, or clothing with someone who has head lice.
If your child has lice, be sure to check policies at schools and daycare. Many places do not allow infected children to be at school until the lice have been completely treated.
Some schools may have policies to make sure the environment is clear of lice. Cleaning of carpets and other surfaces often helps prevent spread of all types of infections, including head lice.
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Elston DM. Arthropods and leeches. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 359
Habif TP. Infestations and bites. In: Habif TP, ed. Clinical Dermatology. 6th ed. Philadelphia, PA: Elsevier; 2016:chap 15.
Kliegman RM, Stanton BF, St Geme JW. Arthropods bites and infestations. In: Kliegman RM, Stanton BF, St Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics. 20th ed. Philadelphia, PA: Elsevier; 2016:chap 668.
Last reviewed on: 2/15/2016
Reviewed by: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.