What Causes Splotchy Skin On Back?

Hi, may I answer your health queries right now ? Please type your query here...I have had splotchy skin on my lower right side of my back constantly for the last six mos. It looks circulatory and is in the same region as a back injury causing compressed discs and a subsequent discectomy on L-4& L-5 . My physical therapist says there is noticable muscle loss in this area also. What might this be?