Steroids, psoriasis and a flare

Morning chaps and chapesses, hope you are well.

I've been on humira for 11 months and it has done sterling work in reducing inflammation levels - single figures since the word go. I have PA, but usually not much of the P part. My last episode of it was Oct 2006, when I had it on my soles, palms and a patch on the inside of my left ankle, which has never really cleared since then. I went to dermatology in Jan 2007 and they told me to avoid taking oral steroids as they were not good for P.

Due to a real slump in the past few weeks my rheum. consultant put me back onto higher doses of prednisalone, starting at 20mg per day, reducing gradually to 7.5. I am curently on my second week of 17.5 per day, and the psoriasis has reappeared, in my scalp (been there before in 1997) and on the sole of my right foot, not huge amounts, but noticeable. My left knee is 3-4" bigger than my right and my right ankle has swollen.

So: can larger doses of steroids trigger a flare? In addition to the humira I am also on 17.5 injected meth per week, naproxen twice daily, omeprazole, sulphasalzine (6 tablets per day) and weekly alendronic acid. I have rung my hospital helpline but they have not yet responded. Any ideas you clever people? Dreamdaisy