How To Treat The Side Effects Of Prednisone?

I am 38yo F 5 4 with history of severe spinal stenosis. About 6 years ago I began smoking marijuana for medicinal puposes. It worked well until I started getting red painful dots on my legs that turned into a flaky itchy rash on my legs. My primary doc said I was allergic to marijuana and prescribed Prednisone. I felt the benifit out weighed the side effect and delt with the rash. The rash continues to get worse. Would marinol give me the same reaction? Is there anything that would help to go away?