I moved to Krakow two years ago - since then, I have experienced what I think are allergies each April/May and September/October. I am not exactly sure since I never experienced this before - no problems whatsoever while living in the States.
it looks like many people get allergies when they change the climate... their body just reacts that way... i've never had any allergies, but my friends who moved to the States from Europe developed allergies, which they try to cure with pills and shots... it's not pleasant...