I know this isnt the same But-One of my guys when younger always seemed to break out in a itchy red rash, we ended up noticing it dissipated when we moved house with no carpets. But she still always itched and carried on if I had been to my sisters and we finally worked out it was the carpet powder we had both been using to help with the doggy odours. :0 her guys are also inside woofa's. She is a dog that is sensitive to heaps though, beef, lamb, corn, too many grains, some shampoos etc. She suffers from hot spots poor babe.
"No amount of time can erase the memory of a good dog or cat, and no amount of masking tape can ever totally remove their fur from your couch"