The Centers for Disease Control reporte Wednesday that about 3 million kids in the United States have food allergies -- up 18 percent in the last decade. That may be because it's being detected more, instead of a true increase. Either way, parents and schools have to be on the lookout for reactions that could be dangerous.

It's the reason you see all those signs in stores now, warning about products made with peanuts. This is the first federal study on food allergies, and advocates are glad it's getting some high-profile attention.

Riley and Shaylyn have severe peanut and egg allergies.

"I can't go to school and eat there and I can't go to restaurants and I can't pick from off a regular menu, kids menu," said the 8-year-old allergy patient.

Their parents have to be ever vigilant to make sure the girls don't accidentally come in contact with the wrong foods.

"Some parents get all excited when their kids go to college. I don't even want to think about that right now," said mother Sherry Mers.

The CDC reports, since 1997, childrens' food allergies are up 18 percent. That's one in 26 kids, almost one in every classroom.

Peanut allergies have doubled, even though twice as many children are allergic to milk and eggs.

"That's one thing we have really lacking right now: information on good exposures, and why some kids develop these allergies and some kids do not," said Amy Branum of the CDC’s National Center for Health Statistics.

They do know it's more common in kids under 5 - and children today take longer to outgrow allergies. Reactions range from mild rashes to anaphylactic shock. Hospital visits have more than tripled since the late ‘90s.

Schools are often the first line of defense:.

"They recognize when a child is having an allergic problem because, maybe, they can't run around the track at school, or they're having difficulty concentrating or breathing in their classroom,” said Mike Tringale, with the Asthma and Allergy Foundation of America.

The Asthma and Allergy Foundation reports most schools around the country are on the ball when it comes to making sure kids stay away from foods that could make them really sick.

The CDC study also found Hispanic parents are much less likely than white or black parents to report food allergies in their children.