I went to to 8 different schools between K to 12th grades in 6 different states, and I don't recall meeting anyone who was deadly allergic to anything. I'm pretty sure I didn't even learn about epipens until maybe later in high school or possibly college.

The only ailment in kids that I think I had heard of was asthma, for which people had inhalers.

Of course, my data is weak and anecdotal, but based on the fact that a staple American food isn't allowed in schools anymore, I assume something must have changed.