I'm being honestly curious here and not trying to be mean or derogatory about this. Since you're allergic to corn, how difficult is it for you to find things tray don't contain some form of corn?
Incredibly. I am deeply grateful that I am not as sensitive as some people I know of in that I can still buy a limited number of known products at grocery stores and tend to be able to avoid bad reactions to airborne contaminants as long as I keep my exposure brief (eg perfume section at the store? Hold your breath and walk fast you'll be fine in a minute. But more than 15 minutes in a room with popcorn? Tachycardia.)
A lot of people fail to realize how contaminated our entire food system is with corn. Globally, but especially in the United States and since it has grown in popularity, China and South Korea (possibly Vietnam and Thailand as well from what I hear but I'm less familiar with the cuisine and common imports/exports)
Medical is particularly difficult to navigate because so many pharmaceuticals come suspended in what are typically corn byproducts (vegetable glycerin, cellulose, various alcohols etc) or along with preservatives or thickeners (most commercially produced citric acid, ascorbic acid, xantham gum) which are produced using a corn medium.
I am not equally sensitive to all of these things but they do cumulatively impact my ability to tolerate further exposure without a severe reaction.
Anyways, I read a lot of labels and have cut certain foods and medications out of my life entirely for my own safety. But I can mostly fake being normal outside of medical settings and having to just keep it out of my living space. Others with less or more severe corn allergies will have wildly varying stories of how they handle it.
Hope this helps answer your curiosity!
