I'm lucky to have no allergy or hay fever with pollen or other allergens Jeff.
Now if I get a snoot full of it or dust or dirt I'll sneeze my ass off like anyone.
My big Stihl blower is my go-to landscape tool, so I've learned to work downwind and use lower power and whatever it takes to avoid walking in big clouds of crud. Low power is easier on the neighbors too as wide open it makes a lot of noise.
Benadryl knocks me out (puts me to sleep).
I have developed a mild allergy to chocolate in my old age. I don't eat that much of it, and most of the time it doesn't bother me, but every once in a while it will send me into a 30-sneeze snot-machine fit. Why this starts in my 70s I have no idea.
I have had no cold or virus or this norovirus crap going around for over 15 years. I do live alone.