I Have Upper Back Pain And A Pimple Breakout On

I have upper back pain and a pimple breakout on my back on the area just around and above my bra line and now my spine hurts in certain places. I checked with a dermatologist a few months ago and she said it was just a rash but it won't go away. Any idea what it might be. I never was prone to pimples or rashs before but last few years have had several but was able to get rid of them with creams. I am using triamcinolone now.