So-called super lice have taken over half the country and are resistant to over-the-counter treatments.

Last year, Shannon Lesnevich received the call from her son's school. Four-year-old Soren had gotten lice from one of his classmates.

"I was like, 'Oh no.' I knew it would take some work to get rid of it," said Lesnevich.

For millions of parents like Lesnevich, the news gets worse. In 25 states, including both Missouri and Illinois, scientists are finding super lice that can't be killed with the chemical used in most over-the-counter treatments. Pyrethroids used to work 100 percent of the time back in 2000, but by 2013, it only worked in 25 percent of cases.

But even super lice are no match for a new weapon used by the Lice Clinics of America. It's called AirAllé.

File: Lice growing more resistant to common treatments

"We use heated air and we dehydrate the lice and the eggs in a single treatment," Claire Roberts, CEO, Lice Clinics of America said. "It takes about an hour, and we guarantee it."

It's FDA approved, costs about $170 and may be covered by insurance.

Dr. Kevin Hatcher-Ross, the Head of Pediatrics at The Vancouver Clinic said there are more treatments that work on super lice.

"There's a pill that you can take twice called ivermectin that often works quite well," said Hatcher-Ross.

He said there's also a cream. But people who want to use the pill or cream need a prescription.

Over the long term, Hatcher-Ross said there is concern that none of the readily available medicines used to treat head lice will work as people continue to use them.

Experts say the best treatment is prevention, and parents should teach their kids a few basics.

"Don't share hats, don't share hairbrushes," Roberts said. "Try to avoid the actual contact with hair or another head. That's how the lice are transferred."

If your child does get lice, experts say you don't have to go crazy sanitizing your house. Just vacuum, especially anywhere hair might have fallen. Wash bedding in hot water and throw stuffed animals and clothing in a hot dryer for 20 to 30 minutes. Lice can't live without a blood supply after 24 hours.

Here are the states where the most resistant strains of lice were found:

Alabama
Arizona
Arkansas
California
Connecticut
Florida
Georgia
Illinois
Indiana
Kansas
Kentucky
Maine
Maryland
Massachusetts
Minnesota

Missouri
North Carolina
Ohio
Rhode Island
South Carolina
Tennessee
Texas
Virginia
Washington
Wisconsin

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