Wellbutrin and prednison

I was prescribed generic Wellbutrin two weeks ago today. I took it for 10 days with no problems except mild headache, mostly pressure. I felt great even after only 10 days and had tons of energy. I know it usually takes 3-6 weeks for the full effects but I was already happy after only 10 days. I thought this was a miracle drug. On the 11th day I had a few hives on my inner thighs and on my chest but I didn't think too much of it. On the 12th morning I had tons on my thighs, entire torso from abdomen to chest, shoulders upper arms, neck and back. I even took pictures to show my doc of the ones of my back. I tried to get in touch with my doc which was this past Wednesday 5/27/09 but his office closed early that day. I then called my pharmacist. He told me to go to the ER immediately. He asked if I was having shortness of breath and I told him I couldn't tell if it was related to meds because I am prone it anxiety and I was a bit anxious about the hives all over. I went to the ER and they gave me a shot of Solu-Medrol (a steroid) in the hip and but me on a steroid (prednisone) pack for 6 days. I only took the prednisone that Wednesday night. Yesterday (Thursday the hives were visible but soo much better, and today (Friday) they are completely gone. I am so disappointed that I had this reaction because I loved taking buporion (generic wellbutrin). I wonder if it's just the generic that does it because I read someone else say that the name brand didn't give them hives but the generic did. I will have to check in to that. The ER doc told me to stop taking so my last does was Wednesday morning. (ohhh by the way I was on 150mg once in morning and once at night, so 300mg/day and I was on the wellbutrin SR kind)