Head Lice

Dear Parent:

In the past few years, there has been an upsurge of head lice in preschools and elementary schools. At least one of every ten children will probably contract head lice by the 6th grade. Contrary to public opinion, the main source of head lice is the family home environment, not the school system. Lice are found in the school system by diligent school teachers or nurses who are aware of the problem.

  • Head lice will attack the clean and the unclean with equal zest. Cleanliness is no barrier.
  • Head lice like the rich and the poor, and all races of people. 12-14 million people each year are affected.
  • Head lice are most common in young school age children, but anyone can get them.

1. What are head lice?
A head louse is an insect that lives on the human scalp and feeds on blood. While feeding, lice inject saliva into the skin which causes itching. They hatch from small eggs, called nits, which are attached to the shaft of individual hairs. The eggs hatch in about 10 days, with the new lice reaching maturity in about two weeks. A female louse can live for 20-30 days, and lay as many as six eggs a day.

Adult head lice are about the size of a sesame seed. Head lice have strong claws to hold on to hair strands. Louse eggs are tightly cemented to the hair strand.

2. Where do lice come from?
Long before recorded history, head lice were living on human beings. Except for occasional strays to close pets, head lice are found almost exclusively on humans. Birds and other mammals (both wild and domestic) have their own lice, but those kinds cause only incidental problems for man. Anyone can get head lice, but they are most often found on young school age children.

3. How does someone get head lice? Head lice cannot jump like fleas. They have no wings and cannot fly. Physical contact between people is a common way they spread. Indirect routes include using the comb or hairbrush of someone who has lice, borrowing hats, ribbons, scarves or other head coverings, sharing towels or pillowcases, sitting in the movie theatre or trying on clothes at stores.

4. What should I look for? Adult head louse (left) and nits or eggs (right)

Persistent itching of the head and back of the neck can indicate head lice. If your child scratches his or her head frequently, or if you hear of head lice occurring on frequent visitors to your home, or on close friends of your child, inspect your child’s hair for:

  • Lice among the hair. Lice and nits are most likely to be found near the scalp where the hair is thickest, usually behind the ears and around the nape of the neck. Lice avoid the light. They grow from slightly larger than the nit up to 1/8 inch in length (about the size of a sesame seed).

  • Nits on the hair. These look like tiny oval objects glued tightly to the side of hair shafts. The length is less than ½ the diameter of the head of a pin.

  • Fecal specks on the collar. Specks are more likely to be seen if the hair is long, the collar light-colored, and lice are plentiful.

5. What is the best lice treatment?
Daily, mechanical removal of lice and nits is essential to successful treatment. Over-the-counter lice preparations containing pyrethrum do kill most lice and nits. Within a few hours after application, pyrethrum breaks down into inactive components. Nix®, a new product containing permethrin (a longer-lasting, synthetic version of pyrethrum), remains active for at least a week. It is the only pediculicide that kills most lice for a week or more (adults at once, and baby lice after they hatch from the eggs) with one proper application.

6. Isn’t 1% Lindane that the doctor prescribes the most effective? No. Lindane is no longer the drug of choice. It may be that lice are becoming resistant to this product. Recent studies show that 1% Lindane is the least effective at killing lice.

7. Do the lice preparations kill all the nits (eggs)? No. Lice preparations kill only 50-70% of the nits. Daily, conscientious nit combing is the best way to rid heads of the nits.

8. What is a “No-Nit” policy? When your child is found with head lice, you must remove all the nits from the hair before he or she is checked again by the school nurse.

9. What is the best way to remove nits? With the following procedure you can remove all the nits with a minimal amount of discomfort for your child. After rinsing the pediculicide out of the hair and scalp, thoroughly massage in a sufficient amount of cream rinse, hair conditioner, mineral oil, baby oil, olive oil, or other nontoxic lubricant. Then comb the hair with a regular comb to remove any tangles. The lubricant makes the job easier and lice and nits will stick to the comb. Next, methodically comb the hair with a special fine-tooth nit comb to remove nits. Be patient. This usually takes 1-2 hours. Rinse and clean the comb thoroughly with an old toothbrush and wash the debris down the sink drain.

10. Which nit combs work best? Metal combs are among the most effective.

11. Aren’t nits located more than ¼ inch from the scalp either hatched or dead?
No. In temperate climates nits can be laid anywhere on the hair shaft.

Treatment of the Individual

Safety must come first when using a pesticide. Always read and follow label directions! Treatment includes applying a pediculicide product and removing the nits from the hair with a fine-tooth comb. Before one family member is treated, all should be examined. Then, only those showing evidence of infestation should be treated. Treat them all at the same time to prevent reinfestation from one family member to another.

1. Remove child’s shirt and use a towel to protect the eyes. Do not treat in the bathtub or shower; instead have the child lean over the sink (this helps confine the lice product to the scalp and neck). First use a detergent-stripping type of shampoo like Prell. Do not use shampoos that contain silicon, or other conditioners. These may coat and protect the nits and lice from the pediculicide. Be sure the hair is only damp, not wet.

2. There are several remedies available at your pharmacy, over the counter or by prescription. Permethrin formulations (like Nix®) are the most effective. Consult your pharmacist or physician if you are pregnant, nursing, or have allergies, using medication, or discover lice or nits in the eyebrows or eyelashes. No pesticide should be used in the eye area. Avoid applying pesticides when there are open wounds on the scalp of the person being treated, or on the hands of the person who applies the product.

3. After treatment, all the nits must be removed. This may be difficult and take a long time, but it is the only way to prevent reinfestation. Even after using Permethrin, 10-30% of the nits might survive. Hatching will occur in 7-10 days, and could result in reinfestation!

4. When nits are all removed, have the child put on clean clothing and let the hair air dry.

5. A nit check twice a day is advisable for at least 10 days after treatment; then checking should become part of routine hygiene. You may have to retreat in 7-10 days if there is any evidence of new nits or newly hatched lice. (Regardless of precautions taken at home, reinfestation from others can still take place).

Treatment itself can cause itching, so do not retreat on the basis of itching alone. A sign of successful treatment will be no new nits being found. Nits are most often attached to the hair shaft near the scalp, but they can be found anywhere on the hair shaft. People used to believe that if no nits are found closer than ¼ inch to the scalp, the infestation was over. This is now known to be false.

Lice have developed resistance to treatment. You could try this home remedy: Wet hair well with Cetaphil cleanser, comb it through the length of hair, and then blow it dry. This will form a hard shell on the hair. Leave it on overnight, and then wash it out. The Cetaphil may smother the nits and lice. See Internet for more details.

Treatment of personal items and the environment Head lice cannot survive off their human hosts for much more than 3 days. Carpets and furniture are not good places for lice to survive. But a nit attached to a fallen strand of hair can hatch several days later and go looking for a blood meal. It is unlikely that it will crawl its way back onto anyone’s head.

Machine wash all clothing and bed linens that may have been in contact with the infested person during the three days before treatment. Articles should be washed in hot water and dried in the dryer. Non-washables can be vacuumed or dry cleaned. Vacuum all carpets. Don't forget the inside of your car and car seat. Change the pillow case every day for at least 2 weeks.

Insecticides in the home
No one recommend the use of insecticidal sprays. They may be harmful to family members and pets, and are of questionable benefit. Natural products sold by Hair Fairies, Lice Schmice or Hair Wizards are safe to use.