What is head lice?

  • The head louse, or Pediculus humanus capitis, is a parasitic insect that can be found on the head, eyebrows, and eyelashes of people. Head lice feed on human blood several times a day and live close to the human scalp. Head lice are not known to spread disease.
  • Head lice move by crawling; they cannot hop or fly. Head lice are spread by direct contact with the hair of an infested person. Anyone who comes in head-to-head contact with someone who already has head lice is at greatest risk.
  • Spread by contact with clothing (such as hats, scarves, coats) or other personal items (such as combs, brushes, or towels) used by an infested person is uncommon.
  • Personal hygiene or cleanliness in the home or school has nothing to do with getting head lice.

Is this a reportable illness?

  • This is not a reportable illness to CDPH but consult with your school nurse to learn more.

What do schools need to do next?

  • Students with suspected infestation may receive a confidential, discreet scalp inspection by a school nurse or an informed, principal-designate school staff member.
    • Active infestation is defined as the presence of live mobile lice and/or the presence of nits (lice eggs) within 3⁄4 inch from the scalp. This situation requires treatment.
    • Nits further than 3⁄4 inch from the scalp may also require treatment. See a health care professional for specific, individual advice.
  • Wide-scale head lice screening within schools is unwarranted and not recommended.
  • Childcare rules: exclude until the morning after the first treatment
    • Students diagnosed with head lice infestation should present to school nurse/staff documentation of treatment upon return.
  • "No Nit" policies that mandate a student be free of all nits before return to school are ineffective and not recommended.
  • Within a household, all infested persons should be treated simultaneously to avoid re-infestations.
  • The most common, “first-line” pediculicides (medicines that kill lice) are topical and over-the-counter. Prescription pediculicides may be required if first-line treatments fail. Connect the family with medical care for follow up if over the counter medications are not effective.