Are you sure you might not have **delayed** allergies?
Did you ever try experimenting with an "acid test" of trying to eat *alot* of raw onions in, say, cucumber salad (or spicy Turkish salad) and see how your sinuses treat you afterward?
For most of my life I thought onions/garlic were fine for me. The only way I found out otherwise, was when once in desperation I took ALOT of raw garlic in hopes of warding off a cold. That's first when I realized it actually *causes* my throat to close off as well as sinus drip.
Otherwise, you betta believe, I would have NEVER known!
It was only after that realization of *delayed* allergy, that at least my sinus/throat problems have been resolved, if not other parts of me.