A new study adds up the hidden costs of food allergies.

RODALE NEWS, EMMAUS, PA—A new study cooks up some statistics that some economists might find hard to swallow: Food allergy costs in the United States are topping out at a whopping $500 million, according to a new study.

The single most costly culprit involves $118 million worth of doctor's office visits, according to a new study published in the Journal of Allergy and Clinical Immunology. ER visits accounted for about 20 percent of the food allergy costs, totaling $45 million.

And it's a growing problem. The United States Centers for Disease Control and Prevention show that food allergies among children have increased nearly 20 percent between 1997 and 2007.

For more information on dealing with food allergies, check out:

• Think you've got a food allergy? Learn how to find out for sure: Your Food Allergy May Be a False Alarm | How to Know If You Have a Food Allergy

• Feel weird after eating certain foods? Figure out whether it's a food allergy or a food intolerance—there is a difference: How to Tell If Your Dinner Could Kill You

• With a few simple steps, you can be a world-class host who doesn't put allergic guests at risk: Prep a Holiday Meal That Won't Trigger Allergies

• Pregnant or thinking about becoming a new mom? Learn how what you eat during pregnancy can affect your child's allergies. Mom's Diet Affects Baby's Allergies