Check for wheat allergy, to include rye and other grains as well...........
I went through allergy testing and had no reaction until something in the plantain family was run on me
I forget the exact name but I was almost on the floor a few seconds later after the guy left for a few minutes.
Kind of like kryptonite and Superman.
The medic saw and ran over to scrub the test off.
I felt normal almost immediately.
Needless to say I did the shot regimen for a few years.
Been ok since.