The mention of gluten intolerance and an itchy rash make me suspicious of dermatitis herpetiformis which is the skin manifestation of celiac disease. You may want to look into getting a skin biopsy of the rash to see if this could be the culprit. But be sure that your physician understands how to do the biopsy -- have to follow special guidelines of staining and immunoflourescence.

Jump to this post