Treating Head Lice

Pediculus capitus or head lice often become a parenting nightmare when they are discovered in a school-aged child. Old wives tales associating head lice infestation with poor hygiene or lack of household cleanliness add an unnecessary social stigma to the disorder. In truth, head lice are parasitic insects that spread readily from one human to another through direct skin contact. Children of primary school age tend to be affected more, presumably because of their close contact during playtime and at school. The National Pediculosis Association estimates that about 12 million cases of head lice are discovered each year.

What are head lice?

Head lice are wingless parasites that live on the scalp. These parasites need to feed on human blood in order to survive. Head lice cannot live on family pets nor can they survive for periods longer than about 10 days without human contact. Lice are unable to fly or jump from one person to another; however, they can crawl. Some of the more common ways of passing head lice from one person to another are by sharing combs, brushes, hats, towels, sleeping bags or bed linens with an infected person.

How will I know if my child has head lice?

The most common symptom associated with head lice is itching of the scalp. When head lice puncture the skin to draw blood for survival their saliva causes itching and may result in a skin rash. If you notice that your child is frequently scratching his or her head, check for lice. At times children can become infected and not complain of itching. If the school notifies you of an outbreak of head lice check your child frequently even if he or she has no noticeable symptoms.

It can be difficult to spot head lice since they move quickly and shy away from bright light. Begin by inspecting the scalp, nape of the neck and the areas behind the ears. Look for small white or yellowish-brown specks that are attached to the hair. Dandruff can sometimes be confused with lice but dandruff is easily removed by flicking, whereby lice and their eggs are not as easily dislodged.

What is the treatment for head lice?

Effective treatment for head lice involves a two-step process. Initially the adult lice are killed and then the remaining nits (eggs) must be removed. Since ordinary shampoo and hair washing will not kill the lice a specially formulated shampoo or lotion called a pediculicide is recommended. Pediculicides containing the chemical permethrin or pyrethrums can be purchased over the counter and are specifically labeled for use on people. Nix® is an example of a commercial product containing permethrin. Other products containing the chemical lindane require a prescription and are best avoided unless recommended by a physician after other pediculicides fail. Consult with your pharmacist or pediatrician before using any of these products since they may not be recommended for small children, children with certain illnesses and conditions or pregnant women.

Generally speaking, pediculicides are applied initially at the time that the head lice are discovered and then again in a week to 10 days. Two applications are needed so that any remaining eggs that may have hatched are killed in a second treatment. Be sure to leave the treatment on for the specified length of time to insure maximum effectiveness.

How are the remaining nits (eggs) removed?

Lice hatch from tiny eggs (about the size of a period) called nits. Nits are smaller than lice and can be white to yellowish-brown in color. Nits can be found on the hair shaft, usually close to the scalp. Since nits are firmly attached with a waterproof and sticky substance they cannot be washed away or destroyed by blow drying the hair. Nits are best removed manually with a comb or special nit-removing device.

The process of removing the nits can be tedious and time-consuming depending on the length of a child’s hair. It is best to divide the hair into four sections. Beginning with one section of hair lift a very small amount and comb from the scalp downward. Be sure that the teeth of the comb are long enough to get deep into the hair, reaching the scalp. As nits are retrieved wipe them off the comb with a tissue and place them in a sealed bag. If necessary, pin up the hair that has been combed to avoid recontamination. It is easier to comb through hair that is wet. After removing all identified nits rinse the hair with warm water.

Following the initial treatment, the child’s head should be checked daily up until the time of the second pediculicide treatment, for remaining nits. Children should not return to school or a group childcare setting until you are certain that all remaining nits have been removed. In a survey taken at the 1998 annual meeting of the National School Nurses Association, 83% of respondents reported an increase in lice treatment failures and the nurses cited non-removal of nits as one of the primary causes of treatment failure.

How are other family member treated if one member has head lice and what about treating the home itself?

All family members need to be thoroughly checked if one member has head lice. It is not necessary to treat other members with a pediculicide product unless signs of infestation are found. Treating the environment is however an important step in preventing the spread of head lice. The following precautions are advised in the home:

  • Disinfect all combs and brushes by soaking in hot water (130 degrees) for at least 15 minutes.
  • Machine wash all clothing, towels, bed linens, blankets, etc in hot water and dry for at least 20 minutes on the highest heat cycle of your clothes dryer.
  • Store all other exposed items that cannot be machine washed (like stuffed animals and dolls) in tightly sealed plastic bags for two weeks. Since lice cannot live outside the body for any longer than this time period any remaining lice or nits will have died.
  • Vacuum any affected areas (rugs, furniture, and mattresses) and discard the vacuum bag.

Should I alert school officials if I find head lice on my child?

Yes. The only way to be certain that head lice will not persist is to adequately treat anyone who has them. If you discover head lice on your child, chances are good that someone else in the classroom is also affected. If you alert school officials the school nurse can screen for head lice in the classroom and also alert parents to check their children on a regular basis. Remember that head lice do not imply unsanitary living conditions. You are doing your child, his or her classmates and the teacher a disservice if embarrassment keeps you from sharing information about head lice.