I get it too.

I used to be able to will an itch away. Indeed I can even make something itch and then stop it by thinking about it, but not this itch. It's mainly in two places. The one I'm more comfortable talking about is my upper back. I have to go at it with a bread knife to stop it but it usually works for an hour or two. It's on a pretty tight schedule really and mainly gives me trouble at night. When I'm getting readdy for bed is the worst. If I try to make it stop it gets an ugly pain and the area feels like dead meat. I've never gone past this stage without scratching it. It is in the affected area.

For a while I thought that perhaps it became more sensitive to heat and it was being burned in the shower but cooler water hasn't helped.