That sucks. But you're not alone. I'm allergic to dust, yep dust. It's very embarrassing being in someone's home and having a reaction. My eyes start to water and it looks like I'm crying, then my nose starts to run. How do you tell someone their home is causing your allergies.. I always need to make up an excuse so I won't insult the host, and then I deal with it the next few hours.
It's become so bad that I won't go to anyone's home unless we know each other very well. At least my friends laugh about it. They know when I start to "cry", it's time for a thorough cleaning!