Even though they’re all found in the same aisle at the grocery store, there’s one key difference between tree nuts (which include almonds, walnuts, cashews, and pistachios, to name a few) and peanuts.

In the United States, about one in every 200 people have a tree nut allergy, making it one of the most common food allergies amongst both adults and kids. While most tree nut allergies start in ...