Dermatitis herpetiformis (DH) is a severely itchy skin condition that often starts abruptly, affecting the elbows, knees, buttocks, scalp, and back. It usually starts as little bumps that can become tiny blisters and then are usually scratched off. DH can occur in only one spot, but more often appears in several areas.
While most individuals with DH do not have obvious GI symptoms, almost all have some damage in their intestine. They have the potential for all of the nutritional complications of celiac disease. It is believed by some GI professionals that most DH patients do indeed have celiac disease.
It is unusual to develop DH after a celiac patient starts a gluten-free diet. About 5% of celiac patients will develop DH, either before being diagnosed or within the first year on the diet. The fact that DH can develop even after starting the diet is probably due to the long lasting nature of the IgA deposits.
For more information see the Dermatitis Herpetiformis page.