Instead of squandering money for temporary relief, tackle the problem at its source: allergens in the air.
What can you do? Buy air filters - go to
www.allergybuyersclub.com and purchase any of their multiple air purifiers with HEPA filtration. I wouldn't bother with the UV light stuff...you can easily land filters that can handle large rooms of 15x15ft for $100 each, each with HEPA filtration and pre-carbon filters (that eliminate odor and large particles such as dust).
I have a couple of these purifiers and no wonder why I don't smell my smelly ass dogs around the place!