They came from people actually getting tested now. Would be interesting to see stats on how many of those "positive" tests are actually serious, as in need for medication if one was exposed to the allergen.I've always asked myself where did all these allergies in children 'suddenly' come from? As a youngster, I don't recall anyone I knew in school having allergies other than hay fever perhaps. A peanut allergy was unheard of. It seems in the last few generations, allergies of all kinds have suddenly popped up.
I know people that are diagnosed with a gluten allergy but eat it on occasion will little to no effect. I know of one other that had a positive reaction on a scratch test for beef. They didn't give it up, have been eating beef for years and are fine.