DH is an unusual rash in that it is mostly symmetrical - down the centerline of scalp, stomach, back or on both elbows, shoulders, knees, thighs, etc., and yes, very itchy. And, yes, bothered by gluten in personal care products on your skin. DH is generally in combination with Celiac and Hashimotos, all autoimmune diseases. So if not already, have your thyroid...