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I was not a happy mom last spring when I got a call from the health clerk at my son's school saying she had found lice on his little first-grade head.
While I know the critters carry no diseases and don't cause any actual harm -- but for itching --they're still gross. "I felt a sort of panic and dread," said another mother in my son's class, whose child also had lice. "I hated the idea they could be anywhere; it's so hard to see them."
About the size of a sesame seed, head lice, six-legged parasites that live on the human head, are hard to see. And nits -- eggs that females glue onto hairs near the scalp -- are even more difficult to spot.
But, luckily, lice can't live more than a few days away from the warmth and food the human head provides. And though they are hardy in some ways -- they can survive submersion for up to six hours (that's why swimming and showers don't kill them) -- they can't jump, hop, or fly. In fact, head-to-head contact is usually required for them to spread, says Harvard entomologist Richard Pollack, PhD, and if they're not on a head, they get dehydrated and die very quickly. "After about a day without a meal they starve to death," says Pollack.
Still, when lice show up on a child's head, what's a parent to do? For many, the hardest thing is the guilt and embarrassment that come with an infestation and the worry others will believe they are a dirty family with dirty kids.
If you find lice (I confirmed there were at least four inhabiting my son's hair by using a special metal-toothed "nit comb"), experts advise treating them with over-the-counter medicated shampoos called pediculicides (derived from chrysanthemums). The most common pediculicides are applied to dry hair, left on for 10 minutes, and then rinsed off. Experts consider these products safe as long as they are used according to instructions.
Before treating one family member, check others in the household for bugs. Then treat everyone who's infected at the same time, to avoid passing lice back and forth. Let close friends and schoolmates know to check their own heads (and what to do if they find bugs). Parents should also wash bedding or clothing used by anyone with lice in the 48 hours before treatment to kill any lice that may have somehow come off a person's hair. And though washing a favorite stuffed toy may make sense, extreme cleaning or quarantining of all toys and stuffed animals, while sometimes recommended, is not needed. If parents want to avoid washing everything, says Pollack, "a few minutes in the dryer should kill them ... but make it 20 just to be sure."
Treating for suspected nits (as opposed to actual, live bugs), says Pollack, doesn't make sense because nits are notoriously hard to identify. And nits that are not near the scalp are no longer viable and could be a relic of an old infestation.
Because some nits are resistant to over-the-counter shampoos, parents should treat infested family members a second time, 10 days after the first treatment. That way, if any nits were able to survive the first treatment and hatch, the second treatment will kill them before they're old enough to lay eggs.
If you find lice after two treatments with over-the-counter shampoos, the next step should be a visit to your family doctor, who will likely prescribe a more potent medicine.