When I accidentally eat gluten, I often get a bit of a rash along with my GI symptoms. It is usually my first sign that I accidentally ate something. Mine always show up as little pink dots on my chest, but sometimes elsewhere as well depending how bad it is.
It can sometimes be very mildly itchy, but nothing like people normally describe. Just little pink spots. Which makes me think it's not DH. But it definitely seems to be gluten related.
Then again, I haven't had a huge amount of gluten since I figured out my problem-- so maybe if I had more it would turn into full-blown DH? I've always been curious. But not curious enough to try it!!