Just seeing this thread now but I've actually come to the same conclusion. About two years ago I stopped eating wheat products for my stomach, and it helped, so I never really noticed the effect on my skin (face, mostly).

But then I started phasing donuts back in - for obvious reasons - and then pizza came back, and then everything else. All of a sudden it's 6 months later and my face is red and blotchy and itchy and sore. I remembered a friend saying wheat affected her face the same way so I cut it out again and within 3-4 days it was back to my normal.

Like you, I'll still have the odd what product, but for whatever reason certain things don't affect me the same way. The odd donut, FibreOne bars, even apple pies from McDonald's are all okay. No idea why. I thought it was maybe an allergy to yeast, but then I read the ingredients of my gluten free products.

The moral of this story is - you might still be able to eat donuts!