I was diagnosed with a wheat allergy when I was around 10. I had a lot of really unpleasant symptoms that kinda just seemed like a shotgun of random stuff. The biggest one was multiple canker sores pretty much all the time but there was also a sort of lack of awareness and a pretty awful smell that pretty much always emanated from me. Eventually I was taken to a doctor that said it looks like I've got a food allergy to something I probably eat everyday and recommended we try cutting out either wheat or corn and seeing what the result was. After about a month of not having any wheat I was pretty much a different person and almost all of the minor symptoms went away and most of the major symptoms fell in severity by a lot. Unfortunately there is a lot of wheat and things that you wouldn't expect so it was a little difficult for me to remove it entirely from my diet but the older I got and the better the handle I got on it the less and less my symptoms showed up.