This is a typical hypersensitive reaction. Take tablet cetrizine 1 tablet twice daily for about a week.
You can go ahead and take allegra. But don't use it daily as a routine. Use it whenever you feel you are getting symptoms of allergy.
Wheat pollen allergy has nothing to do with gluten allergy. They might co-exist.
That surgery must have modulated your immune response. Titanium is bio-inert. Normally, it should not lead to allergy. Start exercising. It will help.
You are allergic to pollen grains. You can try using tablet cetrizine twice daily which should help.
They are not becoming more common. But they are now reported more commonly than previously.