FAMILY MEDICINE® COLUMN
By John C. Wolf, D.O.
Associate Professor of Family Medicine®
Ohio University College of Osteopathic Medicine

SHARING HATS, COMBS AND BRUSHES SPREADS HEAD LICE AMONG CHILDREN

Question: My son caught head lice while he was at camp this summer. We got him cleared up, but I'm concerned about him getting them again now that he has returned to school. There has been a chronic problem with lice there. What can I do to prevent him from getting them again?

Answer: Lice are a type of wingless insect that live on humans and most other animals. Fortunately, there are only three varieties of lice that infest humans, and these don't infest our livestock or pets: Pediculus humanus corporis (body lice), Pediculus humanus capitis (head lice), and Phthirus pubis (pubic lice). As you've noticed, these lice are named for the areas of the body where they are usually found. Therefore, your son has had Pediculus humanus capitis.

All of these lice survive by using humans as their food source. They bite the skin, consume blood, and lay their eggs on the unlucky individual. Their entire life cycle requires humans.

The scalp of an individual with head lice has sores where the insects have bitten. While these sores are somewhat itchy, the victim may not complain much about them. The most obvious sign of head lice is the presence of eggs. These eggs, called nits, are small gray-white colored, oval-shaped structures. Each nit is cemented to the shaft of a hair strand at scalp level. As the hair grows, it carries the nit further from the surface of the scalp.

Head lice can live for up to two days off a human host. It is possible to acquire your own personal head louse by close personal contact with someone who has them or by using a pillow, hat or comb of the infested person. The transferred louse then establishes a new home on your head. Children are often infested in this way. The nit can be spread in the same way as the adult louse, but it is even sturdier than the parent. A nit can remain capable of producing infestation for up to 30 days.

Several medicines are effective at killing adult head lice as well as nits. These are usually in the form of shampoos or lotions and may contain -- 1 percent permethrin, brand name Nix; 1 percent pyrethrins, brand name Rid; 1/2 percent malathion, brand name Ovide; or 1 percent lindane. All these medicines work quite well. Each one should be applied according to the their specific instructions. These drugs kill adult lice and nits, but none remove nits from the hair. Repeated combing with a very fine-toothed comb is necessary to accomplish this "nit-picking" task!

To prevent reinfestation, all of the clothing, bedding, furniture, carpets and other items that have come in contact with the infested person's head in the last 30 days -- the period the nit can survive off of a human host -- should be treated. Clothing can be laundered, but an insecticide spray is usually necessary to treat the furniture and carpets.

Lice are a common complication of living in communal groups. Keeping your child inside a plastic bubble will isolate him from another episode of lice. However, I think there is a better and simpler solution. Encourage your son to wear only his hat and to let no one else wear his. He should also only use his own comb or brush. This, plus the preventive measures practiced in schools, is usually sufficient to prevent repeated episodes.

Family Medicine® is a weekly column. To submit questions, write to John C. Wolf, D.O., Ohio University College of Osteopathic Medicine, Grosvenor Hall, Athens, Ohio 45701.