Explain to families that head lice continue to be an ongoing nuisance in the community. Few conditions seem to cause as much concern and anxiety in schools and homes as an infestation of lice in the hair of children. In the minds of many people, head lice are considered almost analogous with filth; but, in reality, these insects do not discriminate according to social class or level of personal hygiene. In addition, head lice are not a health hazard and are not responsible for the spread of any disease.
II. The Head Louse
Lice are parasites of the human host. There are three types of lice which infest humans; the one of concern is Pediculosis Humanus Capitis. Lice are 2-4 mm in length, wingless, gray-brown, hairy, flat insects. Lice are not physically able to hop or leap or jump from victim to victim. Adult lice and newly hatched nymphs swing from hair shaft to hair shaft rapidly as long as they have a rough surface on which to travel. They do not survive for more than a few days away from the source of food.
Individuals become infested by coming into close contact with an infested person, by wearing infested garments, by using infested combs and brushes, or by lying on infested carpets, beds, or upholstered furniture that has recently been used by an infested person. While families play an important role in transmitting head lice, there are limitations to this method of dissemination. For survival, head lice require frequent meals of human blood and without such a meal, lice that have fallen off or have been brushed off the host will die at room temperature 22 degrees C (71.6 degrees F) in approximately 48-55 hours. Thus, they can be transmitted by such objects as hair brushes, caps, scarves, and coats for only a short period of time.
The life span for an adult louse is approximately one month. Adult female lice are capable of laying eggs at a rate of 8-10 per day.
The naked eye cannot discern the difference between live lice eggs and empty shells. Nits, eggs or eggshells, appear white on dark hair and brown or light on blond hair.
III. Legal Basis for Control of Head Lice
Title 28, Health and Safety, Chapter 27, Communicable and Non- Communicable Diseases, Sections 27.71 (11), 27.72, 27.73 are the legal basis for excluding and readmitting children to school in relation to specified diseases and infectious conditions.
- S27.71 (11) specifically relates to Pediculosis Humanus Capitis (head lice) and provides for exclusion of students from school (public, private, parochial, Sunday or other school or college or preschool), who have been diagnosed by a physician or are suspected of having Pediculosis by the school nurse. Exclusion from school is for the period of time until the student is judged non-infectious by the school nurse or by a child's physician.
- S27.72 provides for exclusion from school of pupils showing symptoms judged non-infectious.
- S27.73 provides for readmission to school if the nurse is satisfied that the lice infestation is non-communicable or when the child presents a certificate of non- infectiousness from the physician.
IV. Population at Risk
With the exception of African-Americans, who are rarely infested, all members of society appear to be equally susceptible. The risk of infestation increases with any factor that brings a person into direct contact with an infested individual and his or her personal belongings.
Clinical symptoms of lice infestation are itching of the scalp, back of neck, and behind the ear/s. This itching is caused by the blood sucking of the louse. The itching is often accompanied by infected scratch marks or what appears to be a rash. Occasionally, there may be swelling in the lymph nodes in the neck or under the arms. There may also be mild fever or muscular aches. The above symptoms generally indicate severe cases of head lice.
VI. Epidemiologic Studies Reveal the following:
- The length of hair makes no difference.
- More girls contract head lice than boys.
- More whites contract head lice than African-Americans.
- Elementary school children in lower grades contract head lice more than children in the upper grades.
- Occurrence decreases with age.
- Children from all socioeconomic groups have similar rates of occurrence.
- Children who share lockers have a higher rate of infestation than children who use their own locker.
- There is a greater chance of being infested if one or more family member is infested.
The control of head lice in the home, school or other institutions is similar. Early treatment of infested individuals coupled with a few environmental precautions is the key to interrupting transmission. It is necessary to treat the infested individual and personal articles (e.g., hats, combs, brushes, towels, and bedding). Fumigating and using insecticides in the home, school, and on school buses is not recommended by the U. S. Public Health Service.
- Remove all the child's clothing and place him/her in a bath or shower stall.
- Apply head louse shampoo according to the physician's instructions or the label instructions provided by the drug manufacturer. Several medicated shampoos (pediculicides) are available for head lice: NIX, Pronto, RID, Kwell, R & C, XXX, A-200-Pyrinate, etc. Kwell is available by prescription only. The other preparations may be purchased without prescription from the drug store. No published evidence indicates that one shampoo is superior to the other.
- Have the child put on clean clothing after the treatment.
- Repeat the treatment in 7-10 days as directed. (While the pediculicides mentioned above rapidly kill crawling head lice, they do not kill all the nits. Therefore, the treatment should be repeated in 7-10 days to kill newly hatched head lice. The 7-10 day interval corresponds to the incubation period of a louse's egg).
- All family members and close friends of the child should be examined for head lice. Family members and close friends who have had lice or nits should be treated. A sibling or a parent who shares a bed with an infested child should be treated even if there is no evidence of infestation at the time of the examination. It is recommended that all household members be examined closely and treated as indicated.
- It is not necessary to cut the child's hair.
Decontamination of personal articles and environment:
Since heat kills lice and their eggs, many personal articles can be disinfested by machine washing in HOT water and/or drying, using the HOT cycle of the dryer. Eggs are killed in five (5) minutes at 51.5 degrees C (125 degrees F), and adults succumb to slightly lower temperatures. Home hot water heaters keep water at about 60 degrees (140 degrees F) when the heat selector is set on medium or high. Some water heaters do not sustain the 60 degree C water temperature when several loads of laundry are washed one after the other or when other demands for hot water (e.g., bathing) are made simultaneously. To maintain the water at 60 degrees C or higher, allow time between loads of laundry or baths for the water heater to regain its maximum water temperature. If the clothes dryer is depended upon for disinfestation, dry articles for at lease thirty (30) minutes at the high-heat setting. Some non-washable articles may be disinfested in the dryer if the heat will not harm them.
- Machine wash all washable clothing and bed linens that have been in contact with the child the previous 7 days.
- Personal articles of clothing or bedding that cannot be washed or dried may be dry cleaned or simply placed in a plastic bag and sealed for 10 days.
- Combs, brushes, and similar items can be disinfested by soaking them for 1 hour in one of the pediculicide shampoos, by soaking them for 5-10 minutes in a pan of water heated on the stove to about 150 degrees F, or by soaking them in rubbing alcohol for one hour then washing with soap and water. (Caution: heat may damage some combs and brushes).
- Because lice can live only a short time if they fall OFF the head, the U. S. Public Health Service recommends that the cleaning of carpets, upholstered furniture, etc., be limited to simple vacuuming. Using insecticides or fumigants on upholstered furniture, carpet, bedding, etc., is not necessary.
- Clothing or other personal articles may be placed in a freezer overnight. Freezing temperatures kill lice and nits. Anything that cannot be treated with heat may be placed in a freezer overnight.
- Head lice are not transmitted from animals to humans, or humans to animals. Therefore, domestic pets should not be treated.