Outrage over soaring prices for EpiPen, a life-saving allergy treatment, has drawn renewed attention to the number of children suffering from allergies.
As more children grapple with these ailments, the reasons behind the spike are still being debated. Lots of money is at stake: The diagnosis and treatment of allergies is a nearly $26 billion market, according to data from Grandview Research.
Research from the U.S. Centers for Disease Control and Prevention shows that food allergies in children have increased approximately 50 percent between 1997 and 2011, now affecting 1 in 13 children in the United States. This translates to roughly two students in every classroom.
About 90 percent of allergic reactions come from these eight foods alone: Milk, eggs, peanuts, tree nuts, soy, wheat, fish and shellfish. In total, food allergies cause about 300,000 ambulatory-care visits a year, just among children under age 18.
With those numbers on the rise, a few theories are being explored, including one linked to Western society's obsession with fighting germs. The so-called hygiene hypothesis posits that a lack of exposure to infectious agents early in childhood can create a scenario where the immune system mistakes a food protein as an invading germ.