Head Lice Advisory

Post On: September 21, 2018


Head lice are parasitic insects that are transmitted by contact with an infested person or item such as a rug, couch or car seat and/or by the exchange of hats, clothing, helmets, headphones, or personal hair items.

Head lice are more likely to be transmitted at home than in the school setting.


  • Inspect all family members’ hair thoroughly, especially in areas close to the scalp at the neckline and behind the ears for lice and nits (head lice eggs).  Nits are firmly attached to hair shafts and are usually yellow to white.  The adult louse is about the size of a sesame seed and is greyish-white to tan.  It may be helpful to use a magnifying glass when inspecting your child’s head.
  • Correct identification of actual nits (head lice eggs) is critical. Anything that slides along the hair shaft is not a nit.
  • Crawling lice are difficult to see, but finding nits within a ¼” of the scalp confirms the presence of live lice and the need for treatment.



  • Permethrin or pyrethrins is the active ingredient in most over-the-counter products. The active ingredient of choice is permethrin, which is currently in Nix® cream rinse formulation. Follow the label directions carefully, first washing the hair with a non-conditioning shampoo.
  • Only treat individuals with lice. It is important to apply one treatment per infested person. Do not divide treatments among infested people. Do not treat a second time until at least 7-10 days following the first treatment.   Repeat treatments may be dangerous and are unnecessary.
  • Daily removal of lice and their nits from a child’s hair with a nit or flea comb with long metal teeth is the most effective lice control measure.  Complete nit combing of the entire head has to be performed every day (dampen hair for easier combing) until no more lice or nits are found. Any nits that cannot be combed out must be removed either by picking them out with the fingernails or snipping the hair above where the eggs are attached. A useful method for nit combing is to part the hair into small sections. After each section is combed, secure each section to keep track of what has been combed.
  • If permethrin or pyrethrin products are not effective, consider contacting your health provider about the prescription, Ovide® which research has shown to be very effective.



  • Lice die quickly (within 2 days) without a human blood meal (off a person)
  • Nits take 8-10 days to hatch and then about 9 or more days to become adults and lay eggs


The following may be done to decrease the chance of re-infestation from lice or nits:

  • Clothing and bedding may be washed in hot water (130°F) then dried on a hot cycle for at least 20 minutes.
  • Items that are not washable may be dry cleaned or put in a sealed plastic bag for two weeks to prevent lice hatched from nits from re-infesting
  • Soak combs, brushes, hair bands, and barrettes in rubbing alcohol or Lysol® for 1 hour, or boil for five minutes.
  • Carpets and furniture should be vacuumed.  Do not use household lice sprays.

These measures may decrease re-infestation, but should not be substituted for above treatment.

Adapted from “Guidelines for Parents to Control Head Lice”, California Department of Health Service, 2001

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