As if lice weren’t bad enough, a
growing number are now resis-
tant to over-the-counter (OTC)
treatment. Scary, yes, but not
surprising since doctors have re-
lied on a single compound to kill
the bugs for decades, says John
Clark, a University of Massa-
chusetts Amherst toxicologist.
A few single-treatment prescrip-
tion medications exist. Removing
lice with heat treatment or
those annoyingly tiny combs
also works. You just need the
patience of a saint (or a school
nurse). “I’d recommend a pro-
fessional,” Clark says.
WHAT USED TO WORK
OTC treatments kill lice with neurotoxins called pyrethrins (or the synthetic permethrin). When repeatedly exposed to the drug, bugs evolve a genetic mutation that desensitizes their nervous systems to its effects.
WHY THAT’S A PROBLEM
Populations of lice develop additional defenses until they become completely immune, as is now the case in Argentina and Israel. In March, Clark reported that 99.6 percent of head lice in the U.S. already have the genetic mutation and are en route to achieving superlice status.
WHAT TO DO NOW
OTC treatments kill lice with neurotoxins called pyrethrins (or the synthetic permethrin). When repeatedly exposed to the drug, bugs evolve a genetic mutation that desensitizes their nervous systems to its effects.
WHY THAT’S A PROBLEM
Populations of lice develop additional defenses until they become completely immune, as is now the case in Argentina and Israel. In March, Clark reported that 99.6 percent of head lice in the U.S. already have the genetic mutation and are en route to achieving superlice status.
WHAT TO DO NOW
