A Scout from the troop I used to be associated with had what he said was a severe sesame allergy, but he didn't take it seriously. Careful questioning on his family history led to the detail that his father's brother had died young - "choked on a Big Mac". After I pointed out the ingredients on a Big Mac, he finally started taking his allergy seriously. The bottom line? They used to die.
Okay, that's only part of the story. The other part is that modern hybrid peanuts deliver a larger dose of the key allergens. We cook in peanut oil more than we used to, modern peanuts contain a larger dose of the allergens, and then the kids survive because of epipens. Finally, we're correctly diagnosing what happened more often. Combine all those facts, and it looks like we have more of these problems (and we do because those kids usually don't die young of their allergies).
It is surprising to most to find out that peanut oil does not have the proteins that trigger peanut allergies.