I think I may have found a food allergy as the cause of my itch and rash! When I was on an elimination diet avoiding chicken and eggs, I made beef stroganoff with rice instead of my usual egg noodles. Within 2 hours, I was itchy & sneezy. The next morning, I had eggs and was okay. Last night, I made beef stroganoff with rice, and 1 1/2 - 2 hours later started sneezing my head off, nose got really runny, and wouldn't you know it, started itching like crazy again! 2 nights ago, I had wheat pasta and no itch, no sneezing, so I don't think it's wheat intolerance. In fact, it was a very "calm skin" night.
I have to go through my journal and cross reference all the different ingredients used in my stroganoff that I also use in other dishes, but I may be allergic to RICE. It's not very common here in the States, but I grew up on a lot of rice dishes, and I have a few I make now so there is increased exposure?

I think I may, after the symptoms go away, do my own version of a scratch test, using rice water... maybe.

*** Looking a little deeper, it could also be a sensitivity to MSG. I use beef bullion and packaged gravy for the stroganoff, which has a lot of MSG....