I’ve had the dreaded itch for many years too (19 in fact). I notice it flares and goes, and seems to be something in my diet. Of course, getting hot and sweaty worsen things.
Flare ups seem to be caused by:
– too much sugar
– cow milk
With those 3 out of my diet, it will generally subside. I think it is basically an inflammatory response, but I liked what Slate was saying about the mucus – that makes a lot of sense too. I have often wondered if pH levels in my intestine were part of the problem because it is almost like my skin has been mildly chemically burned!