Tuesday, August 3, 2010

The New Rules of Head Lice: Part 2

Continued from yesterday's post ...
What should you do if your child has head lice? First, all other household members should be checked. So should any kids who were likely to have direct head-to-head contact. Anyone with live lice or eggs close to the scalp should be treated. Anyone who shares a bed with the infested person should also be treated.

Hair care items and bedding that have been in contact with the infested person in the 48 hours prior to treatment should be cleaned. (If it’s been longer than 48 hours, any lice will already be dead.) A temperature of 130 degrees or more (by washing or drying) will kill lice and eggs. Furniture, carpeting, and other fabric covered items can be vacuumed. Pediculicide sprays are not necessary. If there is a concern about eggs surviving and hatching, items that cannot be washed may be placed in a plastic bag for 2 weeks.

Unless there is known resistance in the community, the first step in treatment is permethrin 1% or pyrethrins which are available over-the-counter. Permethrin 1% is the most studied and the least toxic of the pediculicides (lice-killers). Conditioners and silicone-based additives will interfere with permethrin, as will vinegar which is often used in an attempt to loosen nits from the hair shaft. When rinsing off pediculicides, use a sink instead of a shower or bath in order to reduce skin exposure. Using warm instead of hot water will minimize absorption. There are many other prescription medications that can be used if these over-the-counter products fail.
For those who cannot afford or who would prefer not to use pediculicides, wet combing or using suffocation methods can be attempted. An example of suffocation would be applying petroleum jelly to the hair and scalp and leaving it on overnight under a shower cap.

Misapplication is the leading cause of treatment failure. No treatment will kill all the eggs, so retreatment at specific intervals is recommended. Shaving, although effective, is not recommended. Any product that is meant to loosen nits can also damage the hair itself. Acetone, bleach, vodka, and WD-40 do not loosen nits. Please do NOT use kerosene, gasoline, or any other such flammable or toxic substance. They are not effective; they are just dangerous. Do not use products that are meant for animals.

Infested kids should definitely get treated, but they should not be kept out of school. The chance of transmission may not be zero, but it is lower than in other settings where head-to-head contact is more likely. One study at a school where over 14,000 live lice were found showed zero lice in the classroom carpeting. In another study, infested people spread lice to pillowcases only 4% of the time. And remember, head lice don’t carry any diseases, unlike mosquitoes which transmit a large number of diseases.

Just to put things in perspective, dust mites (see photo) thrive in bedding, mattresses, carpets, furniture…anyplace where there are tiny flakes of shedded human skin. Their fecal matter is a leading cause of allergies and asthma exacerbations. They are much more insidious than lice, but they don’t keep kids out of school.

Dr. Tracy Lee
Pediatric Hospitalist
Meriter Hospital
meriterkids.com