Short story: I stopped eating wheat, the hives went away! For a year and a half and counting!
Long story: I began to get hives on my hands, feet, legs, back, after I would perform any kind of activity. Sitting in a cushion chair was ok, but if I sat on a metal bleacher, I would get raised hives that would last 1-2 days. Play golf, my hands would swell to wear I could barely hold the club by the end of the round. If it was hot, it seemed worse.
Went to several doctors and allergists. Nothing conclusive and I was thoroughly tested. If something pressed upon me for any length of time, i would hive-up.
So for ten years I avoided most physical activity, so as to avoid the hives. I put on a few pounds, got some bad numbers from my physical, decided to lose weight.
Based on advice from a friend, I stopped eating wheat. I began losing weight steadily. After about six weeks, it began to dawn on me: I haven't had hives in a while. I purposefully went and did things that would ALWAYS cause hives, and NOTHING HAPPENED!
Sometimes will binge, have some beer and pizza and a brownie or two, and yep, I'll get some hives again. Go wheat free, and they are gone.
The important thing here is that my 'reaction' to wheat did NOT show up on my allergy tests. They poked my back with everything, and it was all fine.
So if you think you aren't allergic to wheat, try giving it up for a while and see if you improve. Good luck, hope it works for you. It's so nice to have them gone.
I don't have any other major health issues. Just hives.