Suggest Treatment For Skin Rashes

I have been taking 10mg aderall xr for a few months helps me stay focused. Lately I have developped a skin rash. Started on my scalp....spprad to my neck and ears....arm pits knees and hips. Benadryl will not do much. I had been consuming moderate amounts of alcohol while I am on the pill. Could this be causing this bothersome rash?