This reaction, which breaks out on the elbows, knees, butt, back, or scalp, may look suspiciously like eczema, but it could be a more serious issue: celiac disease, an autoimmune condition in which ingesting even the tiniest amount of gluten causes your body to attack its own intestines. Up to 25 percent of people with celiac have this rash, known as dermatitis herpetiformis. Many patients have no digestive symptoms. When someone with celiac consumes gluten, the body releases an antibody known as IgA, which attacks the intestines; sometimes IgA also collects in small blood vessels underneath the skin, triggering the telltale rash.
