I have that happen when I ride or hike in areas that have things I'm allergic to - like Ponderosa pines (which was a real pain when I lived in New Mexico!). Might be something in the air you can find only this time of year. Cold does not affect that me that. My nose runs, but I don't sneeze like that, and it stops as soon as I come home.
I find that Claritin helps when it's allergy related. If Benedryl helps, consider some kind of allergy meds. But man, it wiped me out! I was pretty miserable for about 24 hours.
Christine
Life is not measured by the number of breaths we take, but by the moments that take our breath away.
Cycle! It's Good for the Wattle; it's good for the can!