My paint horse has always itched her face even to the point of getting a splinter in the eye. We suspected it could be lime disease or an allergy issue. The allergy test cost money so we decided to try a feed change first. She came off all grain and went to alfalfa cubes, Dynamite (which is a vitamin & mineral supplement-only feed 1-2oz/day), and Omega Horseshine (feed 2-4oz) for some fat. She has stopped itching and her back has loosened up. So she is moving faster through rehab training now. She is turned out 8 hr/day and gets 5 flakes of O & A (5-10% alfalfa) in a nibble net per evening. With your work out and showing schedule, you might have to replace the Omega Horseshine with Dynamite’s HES product. Just contact Dynamite to investigate your options. They are a healthy alternative to the standard grain companies. If your horse is high strung, you might try T/A pellets instead of alfalfa.
Your horse may be allergic to oats, wheat, or corn like a quarter horse in my barn. He is 16-17 hands so he gets a muck bucket filled a 1/4 to 1/3 full of the same ration. The results should be seen in 60 days. Although it will take 120 days for his blood/body to completely change over.
I hope you find the cause instead of masking the effects so he can train and perform at his best.