I have a hypothesis based on my own experiences that this can happen from accumulating something in the body faster than it can be cleared. Could you have been continuously ingesting yellow 6 for a while, to the point that it crossed some threshold?

I wasn't ingesting it any more than a regular person -- but I was surprised to find out how many foods use Yellow 6. It's more orange than yellow. It's also banned in several countries. It used to be in Kraft Mac and Cheese but they replaced their artificial colors with natural ones, which is nice.

One thing I wondered while being allergic to it, was how much could I take before triggering the reaction. It ended up being extremely little. A single dorito chip would set it off. After that, I just cut it out of my diet completely.

Another weird thing is the reaction would last about 45 minutes exactly every time. I'd be sitting on the toilet bent over in agony, watching the clock.

Allergies seem to come and go. My partner developed allergies against many local fruits in her early twenties, to the point where she could barely eat any fresh fruits without her lips and throat swelling up; but most of them subsided in her 30ies and she can now eat almost all fruits again with only minor irritations for some.

You ever get that itch in the roof of your mouth, and you use your tongue to kind of scrape/scratch the roof of your mouth? After I started paying attention to food allergies from this Yellow 6 thing, I noticed I would get this mouth-itch from certain fruits and nuts. Watermelon, almonds, and oranges. Super minor in the grand scheme of things, but never knew this itch was due to an allergy -- just thought it happened randomly. That is one thing that has yet to go away, but I can live with it at least.

Fruit allergies can actually be pollen allergies because the pollen contaminates the fruit. If your partner moved to a different areas which has trees she's not allergic to, or just eats fruits produced from somewhere else than she used to, that may simply be the reason.

I’m dealing with a similar thing with poultry right now. If I eat it too frequently, it gives me ridiculous, flu and allergy-like symptoms. However, now that I’ve basically eliminated it from my diet, I can eat it on occasion without much issue.

It took me forever to figure out because poultry is often a filler meat.

I am very close to the same conclusion. Every time I travel, things return to normal. I always eat chicken at home and never when I travel. I tried eliminating everything else I could think of because chicken was such a reliable staple for me for so many years. My symptoms seem more mild. mostly GI and not much systemic presentation