You should dry your skin with a hair dryer on a low setting, like a hand dryer. It stops the itching because you are not rubbing the skin. I was told by both consultants it was the worst they had ever seen, text book stuff. If it’s caused by your boots it could be that you are allergic to some of the treatments used for curing leather or glue and when your feet get sweaty they are more active. I have now two pairs of wellies I can not wear, but I live in my Crocs.
There is a theory that it is started by the athlete’s foot bug, and I had a bad case of that before it started, and a foot infection but its really weird that it ends up on your hands as well. I use urea foot cream on my hands as well if I get an itch.