I have pretty severe allergies and I use a Sharp Plasmacluster air purifier. I picked this up because my reactions started to get really bad last summer and I'd have the worst reactions (wheezing, shallow breathing, etc.) at home only. Did a ton of research and it rates pretty good for what you pay.
After I bought it, my wheezing stopped after a full day of it cleaning the air and now I just have it on when I sleep.
There are even higher end devices, but I'd give this brand a shot.
Here's the best site I found on reviews for air purifiers:
http://www.air-purifier-power.com/to...purifiers.html