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Head Lice Grow Resistant to Treatments

Researchers Suggest End to No-Nit Policies in Schools

Diagnosing Head Lice Is Tricky

Diagnosis of head lice is not a slam dunk, and misdiagnosis of head lice may play a role in treatment  resistance, says Cindy DeVore, MD, a pediatrician and school physician in New York State and the chair-elect for the Council on School Health of the American Academy of Pediatrics.

"Parents may misdiagnose head lice when they see flecks of dandruff or debris and mistake it for head lice in the face of a classroom parent notification of lice," she tells WebMD in an email. "Because self-treatment has been available, involvement of physicians in the care of a child with head lice tends not to occur, and overuse and misuse of OTC medicines likely have complicated sorting out what is actual resistance and what is simply inadequate, inappropriate, or under-treatment."

Treatment should only be started if there is a clear head lice diagnosis, she says.

Bernard Cohen, MD, chief of dermatology for Johns Hopkins Children's Center in Baltimore, agrees.

"Despite resistance to treatment, I think the most common cause of spread and treatment failure is failure to identify and effectively treat all infested kids."

Preventing Lice Not Easy Either

So if diagnosis is tricky, and lice are starting to outsmart some of the more common treatments, what about prevention?

Lice can't hop or fly. Instead, they crawl from head to head. "Totally preventing head lice is probably impossible, if you have a normally active, social child," Frankowski says. "Head lice is a normal risk of childhood, just like colds and scraped knees."

"Although most lice infestations are spread by direct head-to-head contact, many advise teaching children not to share combs and brushes," she says. That is OK, but "not using helmets for safety because you are afraid of lice is never an option," she says.

"Most cases of head lice are community acquired, often at sleepaway programs or parties, and not uncommonly in the summer," Devore says. "Parents should do regular surveillance of young children, checking the napes of necks, behind ears, and throughout the scalp, looking for signs of live lice or "nits" cemented to hair shafts close to the scalp that are not readily pulled out," she says.

And "if there is a significant outbreak in a classroom of more than 20% of the children, the parent can check with the primary care physician to see whether use of a permethrin rinse on an uninfested child might confer some protection until the infestation in the classroom calms," she says.

Not All In Favor of No-Nit Policies

Although the researchers do stress abandoning no-nit policies to avoid prolonged, unnecessary absences from school, other organizations, including the National Pediculosis Association, still support them. The nonprofit group states that not removing nits is the main reason treatments don't work, and if children with hatching nits are readmitted to school, the head lice outbreak will continue.

"While absence from school or child care is a loss of educational opportunity and an encumbrance to working parents, readmitting an infested child is not the solution," the group states. "A policy for head lice must consider not only the infested child, but also his or her peers who have already been successfully deloused or who have not yet been infested."


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