If you’ve been to a children’s birthday party lately, chances are at least one of the little guests had an EpiPen, a portable needle loaded with epinephrine. It’s standard equipment for a growing generation of highly allergic North American kids: more than three times as many children have food allergies now than 20 years ago. And one out of every three children is now allergic to foods, animals or plants. Something puzzling, and frightening, is going on with our immune systems. The Allergy Fix delves into the latest attempts to fix the allergy epidemic, and highlights some innovative, surprising medical avenues that are sparking hope.