Dermatitis herpetiformis is an extremely itchy rash consisting of bumps and blisters. The rash is chronic, which means it continues over a long period. Dermatitis herpetiformis usually begins in people age 20 and older. Children can sometimes be affected. It is seen in both men and women. The cause is unknown. It is thought to be an autoimmune disorder. Dermatitis herpetiformis is also linked to gluten sensitivity (celiac sprue disease) in the small bowel. Symptoms of dermatitis herpetiformis tend to come and go. Symptoms include: extremely itchy bumps or blisters, most often on the elbows, knees, back, and buttocks. The rash is usually the same size and shape on both sides. The rash can look like eczema. Some patients may have scratch marks instead of blisters. A strict gluten-free diet will be recommended to help control the disease. Sticking to this diet may eliminate the need for medications and prevent later complications. The disease may be well-controlled with treatment. Without treatment, there may be a significant risk of intestinal cancer.