I'd be more likely to suspect 6MP, since it sounds like you've been on the pred for a while. Of course, I know some people get odd reactions when they taper pred, so that might be it as well.
Have you changed your cleaner, shampoo, laundry detergent, etc lately?
Status: Remission since late May 2009!
Symptoms began in November 2008, ~4 weeks after giving birth to my son.
Diagnosed with pancolitis on 1/30/09
Currently taking Apriso (4 pills ONCE!! daily), Rowasa twice weekly, Natural Factors Ultimate probiotic 12/12 Formula, and Zoloft (25 mg).