Showing posts with label head lice. Show all posts
Showing posts with label head lice. Show all posts

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

Monday, August 2, 2010

The New Rules for Head Lice: Part 1

On July 26, the American Academy of Pediatrics updated its clinical report on head lice. It is common in school-aged kids, and it can be found all over the world. It affects all socioeconomic groups, and it can affect anyone regardless of hygiene. Mere mention of it can cause itchiness. It seems that resistance to standard treatments is on the rise. And yet, the AAP is pushing for kids to stay in school despite having lice. What’s going on?

Head lice are tan to grayish-white, and they are 2-3 mm long. Their eggs are even smaller. Their life cycle is about 3 weeks long. They feed by sucking tiny amounts of blood. Sensitization to their saliva as they feed is what makes us itchy, but this can take 4-6 weeks to develop. This means that by the time the diagnosis has been made, a kid in school has already been around other kids for a month. The good news is lice can only crawl; that means that they can only spread by direct contact. They cannot jump from head to head. This is also why brushing your hair will not prevent you from getting lice; it will only reduce the number of lice you are infested with. You are better off not sharing personal items (like hats, combs, brushes, etc.), but this is NOT an excuse to refuse to wear protective headgear. Lice that fall off or are combed off are usually injured or dead. Live lice and nits need our body heat to survive, so they are found close to the scalp (within 4-10mm). Farther than that, live lice only survive up to 48 hours, and eggs cannot hatch.

Many cases of “lice” are actually misdiagnosed. Dandruff, hair debris, dirt, and other insects have been mistaken for lice. This adds to the number of “resistant” cases. School screenings and forcing kids to stay home doesn’t reduce the incidence of live lice. Instead it means lost days in education and missed work days for the parents.

So what are we to do? The AAP does encourage parents to check their kids’ heads regularly and whenever the kids are itchy. Especially after sharing sleeping quarters, like at a camp, child care center, or sleepover. Using a louse comb on hair that is wet (with water, oil, or conditioner) is the easiest way to go about it. Eggs are most easily seen at the nape of the neck or behind the ears. Remember to look close to the scalp!

Please check back tomorrow, as I'll talk more about what to do if you find lice in your child's hair.

Dr. Tracy Lee
Pediatric Hospitalist
Meriter Hospital
meriterkids.com