NEW YORK - Parents are reporting more skin and food allergies in their children, a big government survey found.
Experts aren't sure what's behind the increase. Could it be that children are growing up in households so clean that it leaves them more sensitive to things that can trigger allergies? Or are mom and dad paying closer attention to rashes and reactions, and more likely to call it an allergy?
"We don't really have the answer," said Dr. Lara Akinbami of the Centers for Disease Control and Prevention, the senior author of the new report released today.
The CDC survey suggests that about 1 in 20 U.S. children have food allergies. That's a 50 percent increase from the late 1990s. For eczema and other skin allergies, it's 1 in 8 children, an increase of 69 percent. It found no increase, however, in hay fever or other respiratory allergies.
Already familiar with the trend in food allergies are school nurses, who have grown busier with allergy-related duties, like banishing peanuts at school parties or stocking emergency allergy medicine.
Sally Schoessler started as school nurse in 1992 in New York state, and didn't encounter a child with a food allergy for a few years. But by the time she left school nursing in 2005, "there were children in the majority of classrooms" with the disorder, said Schoessler, who now works at the National Association of School Nurses in Silver Spring, Md.
Food allergies tend to be most feared; severe cases may cause anaphylactic shock or even death from eating, say, a peanut. But many food allergies are milder and something children grow out of. Skin conditions like eczema, too, can be mild and temporary.
It's been difficult getting exact numbers for children's allergies, and the new report isn't precise. It uses annual surveys of thousands of adults interviewed in person. The report compares answers from 1997-1999 to those from 2009-2011.
But experts also said they believe there is a real - and unexplained - increase going on, too.
One of the more popular theories is "the hygiene hypothesis," which says that exposure to germs and parasites in early childhood somehow prevents the body from developing certain allergies.