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