Dermatitis Herpetiformis (DH) is a skin disorder associated with coeliac disease. Coeliac disease (CD) is a disorder of the small intestine caused by an autoimmune response to gluten, the protein component of some grains. Namely, wheat, rye barley, oats. In other words, it is gluten intolerance.

Dermatitis herpetiformis is often referred to as “coeliac disease of the skin”, while CD is referred to as “coeliac disease of the gut”.

DH is characterized by a very itchy skin rash distinguished by the eruption of small papules or blisters. These blisters have a burning, stinging sensation and often occur in crops, taking up to 7–10 days to lose their itching, and then begin to crust. The IgA antibodies produced by the mucous membranes (of the nose, throat, lungs and gut) in response to gluten circulate in the blood stream, settling in the skin causing the intense reaction labeled DH. It is currently believed that oats do not cause HD.

If you have experienced a rash which resembles the above description, the first thing to do is to rule out CD. Coeliac disease is diagnosed firstly by a blood test and then confirmed by a small bowel biopsy. The blood test will reveal elevated antigliadin or endomysial antibodies and biopsy will confirm enteropathy with crypts in the intestinal villi.