News Detail
Just Like Kids, Head Lice are Back in School
11/20/2009 8:21:22 AM
By Andrea Nisley, UNL Extension Educator Dawson County
Millions of children in the U.S. get head lice each year. Identifying infestations is the first step toward controlling this human parasite and stopping its spread.
Identification
Adult head lice are about 1/10 to 1/8-inch long and grayish in color. Immature lice are smaller. Head lice are wingless and cannot fly. They do not jump.
There is a great deal of confusion about what viable eggs (also called nits) look like. Female lice cement eggs to the shaft of the hair, about 1/2-inch from the scalp. Viable eggs, often found at the nape of the neck and above the ears, are brown in color. These eggs are oblong, not round.
When an immature louse crawls out of the egg during hatching, the glue is so strong the shell will remain attached to the hair shaft. This shell is white. School nurses and parents often mistake this spent egg for a viable nit.
There are also other particles confused with head lice eggs, including dandruff, hair castes and gel from hair care products. Studies have shown school nurses and parents frequently miss head lice that are present. They also frequently identify children as having head lice infestations by mistaking spent eggs and other debris in the hair with viable nits. When children are identified as having head lice when they aren’t present, those children may be unnecessarily exposed to pesticide products. They also may be not allowed to go to school so it is important to accurately identify head lice and live nits.
Head lice only feed on humans and do not feed on dogs, cats or other small animals. Head lice primarily infest children, but will also infest parents, who should be checked if their child has lice. Teachers and daycare providers may also be infested.
Environmental Treatments Unnecessary
Head lice spend most of their time on their host because they get all their food and liquid by feeding on blood. Lice begin to desiccate within 12 hours without a host. Experts believe head lice are transmitted from child to child primarily through head-to-head contact. Children with long hair may pick up lice more frequently than short-cropped hair styles.
One head lice researcher conducted a study looking for lice on floors and desks of a school where more than 20% of the children were heavily infested with head lice. He used a special vacuum with a filter to catch the lice. In this study, no lice were found anywhere other than on the children. Because lice are rarely, if ever, found away from children, it makes no sense to spray insecticides in schools or homes. Vacuuming should be all that is needed. In homes, bedding and recently worn clothing may be washed and dried in a hot drier. This kills all stages of lice.
Control
Controlling head lice should be the responsibility of parents. Controlling head lice has become more difficult because head lice are resistant to the most common over-the-counter medications. Even when products are used correctly, some lice will not be killed. In addition, these products will not kill viable eggs. A second treatment should be done 7-10 days after the first treatment.
Combing
After head lice control products are used, parents should comb their child’s hair with a fine nit comb to remove lice and nits not controlled by the product. Vegetable oil or conditioner can be used to lubricate the hair and make it easier to comb. Use a small pair of scissors to clip individual hairs to remove nits.
