Question: What causes Dermatitis Herpetiformis: Skin Manifestation of Celiac Disease (For Health Care Professionals) ?
Answer: Dermatitis herpetiformis is caused by the deposit of immunoglobulin A (IgA) in the skin, which triggers further immunologic reactions resulting in lesion formation. DH is an external manifestation of an abnormal immune response to gluten, in which IgA antibodies form against the skin antigen epidermal transglutaminase. Family studies show that 5 percent of first-degree relatives of a person with DH will also have DH. An additional 5 percent of first-degree relatives of a person with DH will have celiac disease.4 Various other autoimmune diseases are associated with DH, the most common being hypothyroidism.
Source: NIDDK