Dermatitis herpetiformis is an autoimmune disease causing clusters of intensely itchy small blisters and hivelike swellings.
Despite its name, dermatitis herpetiformis has nothing to do with the herpesvirus. In people with dermatitis herpetiformis, glutens (proteins) in wheat, rye, and barley products somehow activate the immune system, which attacks parts of the skin and causes the rash and itching. People with dermatitis herpetiformis often have celiac disease (see Malabsorption: Celiac Disease), which is an intestinal disorder caused by sensitivity to gluten, although they may not have symptoms from the celiac disease. People also have a higher incidence of other autoimmune diseases, such as thyroiditis, systemic lupus erythematosus, sarcoidosis, and diabetes. People with dermatitis herpetiformis occasionally develop lymphoma in the intestines.
Small blisters usually develop gradually, mostly on the elbows, knees, buttocks, lower back, and back of the head. Sometimes blisters break out on the face and neck. Itching and burning are likely to be severe. Anti-inflammatory drugs, such as ibuprofen, may worsen the rash.
Diagnosis and Treatment
The diagnosis is based on a skin biopsy, in which doctors find particular kinds and patterns of antibodies in the skin samples.
The blisters do not go away without treatment. People are usually placed on a gluten-free diet (a diet that is free of wheat, rye, and barley). The drug dapsone, taken by mouth, almost always provides relief in 1 to 2 days but requires that blood counts be checked regularly. Once the disease has been brought under control with drugs and the person has followed a strict gluten-free diet for 6 months or longer, drug treatment usually can be discontinued. However, some people can never stop taking the drug. In most people, any reexposure to gluten, however small, triggers another outbreak. A gluten-free diet may prevent the development of intestinal lymphoma.
Last full review/revision September 2008 by Julie E. Russak, MD