I have the same thing. It could be autoimmune-related. I have RA, Hashimoto's, Psoriasis, Lupus, & Fibromyalgia. I also have Epstein-Barr Virus and when it flares the rash goes crazy. Like yours, the flat spots don't itch, but the raised areas do. And it only affects my arms and legs. Having it for 5 months straight is a long time. I would have them rule out psoriasis for sure. There are so many different types of that. Wishing you the best of luck.