Did you ever trade lunches at school when you were a kid? Maybe you gave away your peanut butter sandwich in exchange for some chocolate pudding. With rampant food allergies, a trade like that probably wouldn't happen today. And while schools and other organizations are very aware of the increased number of people who have allergies, we know little about what causes them.  

We talk to Dr. Wayne Shreffler, the director of the Food Allergy Center at Massachusetts General Hospital and Dr. Katie Allen, the Group Leader of Gastro and Food Allergy at Murdoch Children's Research Institute in Melbourne, about the rise of food allergies, how to prevent them, and treatments that are in the pipeline.