Chapter 5

Medical Highlight: Head Lice- A common nuisance

Head lice, also called pediculus humanus capitis, are parasitic insects found on the heads of people. This condition is very common and effects millions of people each year. You can practice good hygiene and still have head lice.

Risk Factors

This condition is found most frequently in preschool and school-age children 3-10 and their families. Girls are more susceptible than boys are. Anyone in close contact with someone or someone’s clothing who already has head lice can be infected, e.g.children frequently switch hats with each other.

Three forms of head lice are:

Nits. These are the eggs. They are hard to see and are often confused with dandruff, but unlike dandruff they can’t be easily brushed out of the hair. They are firmly attached to the hair shaft. They are oval and usually yellow to white. The eggs take about a week to hatch.

Nymph.The nit hatches into a baby louse,ornymph, which matures into an adult in about 7 days. To live the nymph must feed on blood.

Adult. This adult louse is about the size of a sesame seed and is tan to grayish-white in color. Adult lice can live up to thirty days on a person’s head. The adult louse must feed on blood.

Signs and Symptoms

  1. Tickling feelings of something moving in the hair
  2. Intense itchingd cause by the allergic reaction to the bites
  3. Irritability, sores on the head caused by scratching
  4. Head lice are most frequently found behind the ears and near the neckline at the back of the neck

Diagnosis

Diagnosisis made by looking closely at the hair and scalp under a bright light or magnifying glass for nits and lice. Using disposable gloves,separate the hair into small sections down to the scalp, looking both for moving lice and nits. Inspect the entire head this way checking carefully the areas around the nape of the neck and ears.

Treatment for Lice

  • Before treatment remove all clothing from the waist up to prevent lice from dropping on clothing.
  • Use lotions or shampoos designed to kill lice. Apply according to package directions. The lotion and shampoos are designed to kill only the adult lice not nits.
  • Use a fine tooth comb to comb through hair.
  • Have the infected person put on clean clothing after treatment.
  • After treatment check hair every 2-3 days and use a fine tooth comb to remove any nits or lice seen.
  • Retreat in 7-10 days.
  • Check all treated persons for 2-3 weeks after you think that all lice and nits are gone.

Treat the Household

  • Machine wash all washable clothing and bed linens that the infected person came in contact with during the 2 days before treatment. Use the hot water cycle on the washing machine. Dry laundry using the hot cycle for a least 20 minutes.
  • Dry clean clothing not washable.
  • Store all clothing, stuffed animals, comforter, etc. that cannot be washed into a plastic bag and seal for 2 weeks.
  • Soak comb and brushes for 1 hour in rubbing alcohol, Lysol, or wash with hot soap and water.
  • Vacuum the mattresses, pillow, upholstered furniture, carpets, and floor.
  • Do not use fumigant spray. They can be toxic if inhaled.

Schools have policies in regard to when a child with head lice can return to school. Check with your local school if a child has this condition.

References

Centers for Disease Control. (2004). Treating head lice infestation. Retrieved November

5, 2004 from

Author. A common nuisance. (2004). Mayo Clinic Health Letter, 22(9), p. 7.