Can a skin rash be associated with celiac disease?
Dermatitis herpetiformis (DH) is an itchy, blistering skin condition that is a form of celiac disease. The rash usually occurs on the elbows, knees and/or buttocks, and is characterized by its bilateral nature; both knees (and/or both arms) are affected, seldom just one. Many people with DH have no digestive symptoms and only about 40% of them have the positive blood tests (serology) for celiac disease. However, they almost always have the same, gluten-dependent intestinal damage as those with more common symptoms of celiac disease.
DH is diagnosed by a skin biopsy, which involves removing a tiny piece of skin near the rash and testing it for the IgA antibody. DH is treated with a gluten-free diet and medication to control the rash, such as Dapsone or Sulfapyridine. Drug treatment is short term, usually until the gluten-free diet begins to relieve symptoms. It’s not necessary to perform an intestinal biopsy to establish the diagnosis of celiac disease in a patient with DH; the skin biopsy is definitive.