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HEAD LICE: A GROWING PROBLEM

Among the many trials parents must endure are head lice appearing on their school-age children. Because lice have become more tolerant of insecticidal shampoos and infestation is widespread in some schools, successful treatment requires a combination of practices - daily combing with a special lice-removal comb and hand inspection of the hair. Above all else, elimination of lice requires time and patience.

Life Cycle of Head Lice

Mature female lice generally lay their eggs close to the scalp, one egg per hair. (In warm climates, or if the child has a fever, the egg may be laid farther down the hair shaft.) The egg, or nit, is coated with a gluelike substance that cements it to the hair. The eggs hatch within ten to twelve days. Once hatched, females need ten to fourteen additional days to start laying eggs. The approximate total lifespan of a louse is twenty-five days.[136]

Transmission

Head lice can move rapidly but cannot jump or fly. Most lice are transmitted when an infested person comes into direct contact with other individuals. For example, when children sleep together, enough time is provided for a louse to walk from head to head. Lice and their eggs can also be transferred via infested brushes, combs, caps, hats, scarves, coats, bedding, towels, upholstered furniture, and sponge earpieces on headphones. Head lice cannot live more than twenty hours off the host at room temperature; eggs attached to hairs may remain viable for up to ten days but must find a meal within hours of hatching.[137]

Detection

To the untrained eye, nits may be hard to recognize. With a bright light, carefully inspect your child's scalp. A magnifying glass is very helpful. Nits are normally found within a quarter inch of the scalp (although they can be found farther down on the hair shaft). Viable nits are yellowish to gray, darkening to a tan or coffee color as they mature. Empty egg casings are yellow or beige to white. A nit can be easily distinguished from a flake of dandruff or a speck of dust because it will stick to the hair. In other words, if what you see can be easily removed, it is not a nit. The itching associated with head lice arises from the allergic reaction caused by lice saliva. Some people may not experience itching for several weeks.

Treatment

Successful treatment requires determined parents. Once lice are detected, plan on spending one full day for initial treatment. Thereafter, expect to spend at least one hour per child daily for two weeks. After that, continue to check your child's hair every three to four days for several weeks.

Initial treatment of the child involves a shampoo with water as hot as tolerable, followed by combing of wet hair with a fine-toothed metal lice comb. You can consider using an insecticidal shampoo if the initial infestation is severe. This is not necessary, though. Shampoo, due to the insecticidal properties of soap, is sufficient.[138] (Do not use products containing lindane. It is suspected of causing neurological damage, and lice have become resistant to it.) If using insecticidal shampoo, follow label directions exactly; do not treat for longer periods of time or more frequently than the directions specify. Individuals allergic to ragweed may experience a possible allergic reaction to over-the-counter lice treatments containing pyrethrins, which are derived from chrysanthemum flowers.[139]

Shampoo hair before treatment so insecticide will penetrate lice. Use a basic shampoo without conditioners, detanglers, or silicone. Towel-dry hair before applying the product so the treatment is not diluted. In the last few years, the efficacy of pesticide shampoos against lice has apparently declined, judging by the increasingly common outbreaks of lice and the reported ineffectiveness of over-the-counter treatment products. No good studies of product efficacy in humans have been done in recent years.

After shampooing, comb the hair with the lice comb. You may need to initially detangle with a regular comb. With a towel over your child's shoulders, pass the lice comb through one-inch sections of hair. After each pass, dip the comb in a dish of warm, soapy water to remove the nits. Then manually inspect the hair. The combs, regrettably, are not as effective as hand removal. The only way to eliminate lice is to physically remove all the nits. Be sure to launder towels immediately in hot water, followed by high-temperature drying.

Since head lice wander from head to pillow, headwear, stuffed animals, and such, treating these items at the same time as the initial hair treatment is essential. Clothing, bedding, and other washable items will be successfully deloused by machine-washing with hot water and at least 30 minutes in the dryer on high. Do not forget the cover of the car seat, bike helmet, or sponge earpieces on headphones for computers, cassettes or CD players. Items that cannot be washed or dried can be stored in airtight plastic bags for two to three weeks. Another option is to place items in the freezer for ten hours (space permitting). Remember that head lice do not wander far from the head. A frenzy of laundering, dry-cleaning, washing furnishings and rooms does not substitute for treatment and nit-picking.

For the next three weeks, plan on a daily shampoo, combing, and hand removal of nits. Each morning, place your child's pillowcase and any stuffed animals residing in bed in the dryer for 30 minutes on high heat. (High-temperature heat kills lice.) Use an engrossing arts and crafts project, video, or book to engage your child during the combing process.

Additional Advice

Never treat infants with insecticide-based shampoos. Minimize body exposure to insecticide-based shampoos by treating the child's hair in a sink. Children can lie on the kitchen counter with their hair in the sink. This allows use of the spray hose. Do not use a pesticide in the bath or shower. Do not use head lice insecticides preventively. Overuse of insecticides will make lice more resistant to the chemicals.

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