The "Nit"- ty Gritty about Head Lice (Pediculosis)

Head Lice (Pediculosis)
The Bartholomew County Health Department (BCHD) follows the Centers for Disease Control and Prevention (CDC) recommendations for diagnosing and treating head lice. Having head lice is very common; as many as 6-12 million people worldwide have head lice every year. Anyone who comes into close direct contact with someone who already had head lice, contaminated clothing, other belongings is at risk for getting head lice. The population greatest at risk tends to be children ages 3-10 years and their families.

General Information
Lice have three developmental stages: 1) the nit, 2) the nymph, and 3) the adult. Nits are the head lice eggs. They are difficult to see and to properly diagnose. The eggs are oval and range in color, but are usually yellow to white and take about one week to hatch. The nit hatches into a little louse, or a nymph, which resembles an adult louse but is smaller. To live, the nymph must feed on blood within 24 hours after hatching. After the nymph matures, in about 7 days after hatching, it becomes an adult louse. The size of an average adult louse is comparable to a sesame seed. And the females are generally larger than the males. The adult louse has six legs, no wings, and it tangrayish white. Depending on the shade of hair, the louse may appear lighter or darker. The life expectancy of an adult louse can be up to 30 days. Only the female louse can lay nits, and it can lag 4-5 eggs a day if it remains on the person's head to feed. If the louse falls off a person, most of the time it dies within hours because of the lack of feeding and the decrease in temperature that must be maintained to survive. However, some studies have shown that lice can survive up to two days off a human source. Head lice are most commonly found on the scalp behind the ears and near the neckline at the back on the neck, but are rarely found on the body, eyelashes, or eyebrows. They hold on to the hair with hook-like claws found at the end of their six legs. The first signs and symptoms of a lice infestation is the tickling feeling of something moving in the hair and itching. The itching is caused by an allergic reaction from the bite. In some cases there may be sores on the head that have been caused by scratching and can become infected. Lice cannot jump from person to person. Their legs anatomically cannot jump. However, they can move very fast and can tumble over, which may be the reason that people perceive them as jumping. Lice may be transmitted through close play, sports activities where equipment is shared, and wearing infested clothing, couches, carpet, pillows, or plush toys that have recently been in contact with an infested person.

Proper Diagnosis
Lice are diagnosed by looking closely through the hair and scalp for nits, nymphs, or adults. Finding an adult or nymph may be a difficult task; there are usually few of them and they can move quickly. According to CDC, if live lice are not seen, finding nits closer than ¼" from the scalp confirms a person is infested. However, if a nit is more than ¼" from the scalp the infestation is an old one. The rationale for this is that the adult female louse lays her eggs at the base of the hair shaft, and the eggs and lice need to maintain a consistent temperature. As the hair grows, the nits that are at the base of the hair shaft cannot maintain a constant temperature. Generally, hair grows ¼" per week. The optimal temperature for louse survival happens to be the temperature that is maintained on top of heads. If one is not sure if a person has head lice, a health care provider, the local health department, or school nurse should make the diagnosis. In many cases, a child may be said to have a nit infestation, but when the nit is sent to the lab it is actually dandruff, hair spray droplets or some other particle. Therefore, a proper diagnosis is important before treatment is administered. Often, children are sent home from school and parents unnecessarily take time off work because of an improper diagnosis.

Clinical Treatment
Treating head lice correctly has many steps, which must be thoroughly completed to avoid being unnecessarily reinfested. If children less than 2 years old have an infestation, contact your doctor. After a correct diagnosis of head lice, the individuals should remove the clothing and apply the lice medication according to the label instructions. Clothing should immediately be washed with soap and hot water. DO NOT use a crème rinse or combination shampoo/conditioner before using the lice medication. At the present time, the BCHD recommends "Nix Crème Rinse" as a treatment for lice. Nix is available at drug stores and convenience stores, and can be purchased without a prescription. DO NOT re-wash hair for 1-2 days after treatment. The infested person should then put on clean clothing after treatment. Is some live lice are found 8-12 hours after treatment, but are moving slower than before, do not retreat. Comb dead and remaining live lice out of hair with a lice or flea comb. If no dead lice are found or the lice seem as active before within 8-12 hours after treatment, the medication may not be working. Patients should see a doctor for a different medication and follow the treatment instructions. After treatment, comb and remove all nits from the head every 2-3 days to check for the presence or absence of lice or nits. Retreat with medication 7-10 days after original treatment if there is a live infestation. It is a common practice to have to perform at lease two treatments to get rid of head lice. DO NOT retreat more than 3 times, and do not mix lice medications. If there are other family members who are not currently infested, DO NOT treat other family members until there is confirmation of an infestation. However, their heads should be checked every 2-3 days until the infested person is clear of lice and nits.

Environmental Household Treatment
All washable clothing and bed liners in contact with the infested person two days prior to treatment should be washed in hot soapy water (130 F). Dry the laundry using the hot cycle for at least 20 minutes. Clothing that the infested person directly touched for two days prior, which are not washable, should be dry-cleaned. All clothing, stuffed two days prior, which are not washable, should be dry-cleaned. All clothing, stuffed animals, comforters, and other items that cannot be washed or dry-cleaned need to be placed in a plastic bag and sealed for one week. All combs, brushes and other hair accessories, should be washed with hot soapy water and soaked for 1 hour in rubbing alcohol. Lice can temporarily live on carpet, car seats, and upholstery, which should be thoroughly vacuumed. It is not necessary to spray insecticide or lice spray to these surfaces because they can be toxic if inhaled. Vacuuming these areas is just as effective and a lot less expensive and safer. Pets should not be treated for head lice because lice only live on humans.

Prevention
Future prevention for the control of lice infestation is possible through health education of parents, students, and school personnel.  back