I find it infuriating how arrogant and counter-logical American nutritionists are on this issue. They believe that any allergy will show up if you merely put a piece of food in your mouth, and do so almost instantly. For them, the oral challenge is a golden test which always works: https://www.foodallergy.org/diagnosis-and-testing/oral-food-...

"If you have no symptoms, food allergy can be ruled out."

Some of this is obstinate pendanticism about what the word allergy means, but mostly it is just arrogance and refusal to understand reality and logic.

I for example, will throw up in the evening if I eat a large portion of barley for lunch. Obviously, I shouldn't eat barley and my European doctors have no trouble understanding that. But according to American medicine, there is no problem since I obviously pass the oral challenge for barley.