What Could Constant Itchy Body With Dryness Suggest?

i have had itching in the trunk area of my body, my waistline, in the front for about a month now. It started with a very small area that was itchy and then red and then the skin turns brown. This has spread all across the front of my trunk. It is about two inches wide and runs across the front of my body. I kept chalking this up to winter time dryness but i am concerned that it is speading and my skin color has changed. Any ideas?