Grace has it! I have the same problem with sulfites. I've been in the ER too many times.
Is there any medicine you can carry, maybe Benadryl or even an Epi-pen, that will rescue you? I have to carry a heart med, Inderal, for my reaction. I needed it yesterday after eating some Kirkland brand cashews.
There are some websites where you can look up allergen content by chain restaurant. Maybe check the archives. I don't know the sites offhand.