Treating Head Lice
Monday, April 26, 2010
Treating Head Lice
In our very open society, few topics remain unmentionable. But bring up head lice and watch the room clear. The mere thought of creepy crawlies invading one's hair is enough to make most people squirm, and head lice also enjoy an association with uncleanliness and sub par personal hygiene. To make matters worse, the little beasties can be very difficult to eradicate. Kudos then, to the New England Journal of Medicine, for wading into this distasteful morass to offer help. Oral ivermectin versus malathion lotion for difficult to treat head lice examines the most effective way to get rid of the buggers when they are loath to go.
More than 800 children who had already failed treatment with an insecticide-containing shampoo were divided into two groups, one of which received an oral medication called ivermectin, while the other was treated with a shampoo containing an insecticide called malathion. Turns out the oral medication was better at eliminating the infestation than the shampoo. Better than 95% of those who received ivermectin were cured, while among those who used 0.5% malathion shampoo, 85 to about 89% responded. Looks like ivermectin is the superior choice.
Rick points out in the podcast, however, that simply switching wholesale to treatment with ivermectin is likely to result in more resistant organisms, so sticking with the original strategy of trying commonly available shampoos first is probably best for all concerned. Other things to keep in mind to improve one's chances of success include treatment of all household contacts simultaneously and washing all bedding and items that may have come in contact with an infested person's head in hot water.
A minimum of two treatments is required, whether topical or oral medications are used, and they must administered according to a strict timetable. That's because the first treatment kills the adult lice and the second the eggs, or nits, that are attached to the hair shaft. The second treatment is timed to coincide with emergence of the nits, and not treating accordingly is a common cause of treatment failure.
It's worth blowing a few urban myths out of the water here for parents of kids who come home with head lice. Personal hygiene is a non starter. Kids 3-11 and their families are most likely to become infected and that's because kids share hairbrushes, wear each other's hats and the like. It's much less likely to become infected from the back of a couch or a pillow where an infected person's head has been. So tell your kids that when it comes to hats and hairbrushes, sharing is not a good thing.