1 SEPTEMBER 2005
Nit Wit
School's back. Time to sharpen those pencils, unearth that backpack and let the learning commence! (Or, if you are more like us, hit the snooze button for another fifteen minutes...) Along with the usual harbingers of the new school year, there is another, more sinister and positively medieval sign that school is back in session: head lice.
With the clamoring of that first bell for homeroom, parents should keep a diligent eye on the tops of their child's lil' punkin head for these most foul creatures. Though they cause no serious medical problems, the itchiness associated with head lice leads to gaps in concentration and restless, sleepless nights, making school all but impossible.
It's scalp tingling! Seen here magnified many times, this louse looks the part of a blood-sucking monster. Illustration by Dennis D. Juranek CDC
Once infected, a child with lice can carry scores of the creepy critters around. According to the CDC, there are no reliable data on how many people get head lice in the United States each year, but there are an estimated 6 to 12 million cases annually. The exact number of cases of head lice in the US is unknown mostly due to the social stigma of infestation.
One of the most enduring myths about head lice is that an infested child must be sent home or isolated from his or her peers. Lice are most easily transmitted by head-to-head contact and it has long been believed that one head conk on the playground could start an elementary school epidemic. In the US, many schools have adopted a "No Nit" policy where students are prohibited from participation in school until the nits have been completely removed. It's estimated that 12 to 24 million school days are lost each year due to a head lice infestation.
It's scalp tingling! Seen here magnified many times
with an electron microscope, this louse looks the part of a blood-sucking monster. Photo
by Vincent S. Smith, University of Glasgow
Itching for a Solution
Humanity has curbed the bubonic plague, polio and smallpox, but, to every parent's
dismay, head lice have proven to be especially problematic pests to eliminate.
Lice quickly become resistant to over the counter chemical treatments and fine
combing a child's hair is a time-consuming hassle. What's a parent to do? Researchers
from the London School of Hygiene & Tropical Medicine suggest that, hassle or not, combing is the most effective way to control head lice. 
I'm gonna comb those nits right outta your hair...
Published online in the British Medical Journal, researchers state that combing is four times more effective than chemical treatments in controlling head lice.
Sometimes called "bug-busting," combing for lice is a tiresome, but effective practice of ridding a child of an infestation. First, the hair is coated with conditioner, then separated and held into place. Then, working over the head one section at a time, an extremely fine-toothed comb is used to comb out the lice and eggs (sometimes called nits). Combing should be repeated four or more times to ensure that all of the lice are gone. It is an arduous process that is not for the quick tempered.
Or the long haired.
For these reasons, chemical treatments are often the preferred method of control.
Usually applied in the form of a shampoo, chemical treatments over-stimulate
the nervous system of the lice, leading to eventual paralysis and death.
Unfortunately,
chemicals are less successful against the nits and several applications of
the harsh chemicals are needed.
Actual size of the three lice forms compared to a penny. Image: CDC
Many parents balk at the thought of coating their children in poison and fail to follow through with the applications. Just like bacteria, lice can then develop resistance against the chemical treatments used to kill them. Once resistance is developed, it can be passed on to offspring, making defeating the little beasties all but impossible.
So, while it is time-consuming and tedious, combing is four times more effective than chemicals and no louse is comb resistant.
And if that fails, there is always head shaving.
-- Megan Anderson
Bibliography
Nowak, R. (2005) Hair Wars. New Scientist, Vol. 184. Issue 2479/2480.
Price, J.H., Burkhart, C.N., Burkhart, C.G., & Islam, R. (1999) School nurses' perceptions of and experiences with head lice. Journal of School Health Vol. 69.
Scott, P., Gilmer, M., & McNay Johannessen, W. (2004) The Nit Rating Scale. The Journal of School Health, Vol. 74, Issue 3.
