I sware I already replied to this so I am not sure where my post went. Anyway.....

In the winter your skin tends to get very, very dry. I can scratch my legs raw from dry skin. Could this be what the problem is? What has helped me is Hemp oil lotion. i bought it from a specialty store. It's a little pricy but has help so much with my dry skin. I apply it after my bath and it has worked wonders. Maybe give it a try.

Also, I didnt know if this is some type of compulsion or something along those lines. Where you are really having a hard time not scratching. Please clarify or feel free to PM me if needed. Take care. Much Luv!!