Dermatitis herpetiformis (DH) is an intensely itchy skin disease. It causes clusters of small blisters and bumps. Symptoms typically start at age 30 to 40, but can happen at any age. This chronic autoimmune skin condition is rare in children. It affects more men than women.

Despite its name, the herpes virus doesn't cause DH.

DH is caused by a sensitivity or intolerance to gluten. Gluten is a protein found in wheat and grains. When you have DH and eat food with gluten, the gluten sets off an immune reaction. This causes material called IgA antibodies to go into the skin. That's what causes the rash.

DH is found most often in people of northern European heritage. These diseases increase your risk of DH:

• Autoimmune thyroid disease.
• Celiac disease.
• Type 1 diabetes.
• Sjögren syndrome.
• Lupus.

Each person may have different symptoms. The most common ones are:

• Clusters of itchy, small blisters and bumps, mostly on the elbows, lower back, buttocks, knees, and back of the head.
• Severe itching and burning.
• Often, erosions and scratches on the skin.

The gut may also have the same allergy to gluten. This is known as celiac disease. You can have both DH and celiac. Some cases of celiac become cancer. Because of this, if you have celiac disease, it's important to see a doctor who specializes in the stomach and intestines (a gastroenterologist).

The symptoms of DH may look like other skin conditions. Always talk with your doctor for a diagnosis.

Your doctor will ask about your health history and give you a physical exam. DH is usually confirmed with a skin biopsy and a lab test with a special type of stain that helps detect the IgA antibodies. You may also have blood tests to find certain antibodies.

DH may be well-controlled with treatment.

Treatment will depend on your symptoms, age, and general health. It will also depend on how bad the condition is.

The symptoms of DH may go away if you cut all gluten from your diet. Healing may take several weeks to months. Your doctor may also prescribe a medicine called dapsone. This medicine suppresses the skin response and may improve symptoms. But the medicine has some side effects, including anemia. If dapsone is prescribed for you, your doctor will carefully watch your blood count.

There is no known way to prevent this disease. You may be able to prevent complications by staying away from foods that contain gluten. Sticking to a gluten-free diet can reduce the amount of medicines needed to manage the disease.

People with DH often have celiac disease, which may develop into intestinal cancer. Thyroid disease may also develop.

It's important to follow your doctor's advice about a gluten-free diet and medicines. Iodine and some nonsteroidal anti-inflammatory drugs (NSAIDs) can set off the condition. So you may be told not to have iodized salt and certain NSAIDs.

Contact your doctor if your symptoms get worse or you have new symptoms.

• Dermatitis herpetiformis (DH) is an intensely itchy skin disease. It causes clusters of small blisters and small bumps.
• DH is caused by a sensitivity to gluten.
• There is no known way to prevent this disease
• The symptoms of DH may clear when all gluten is cut from the diet.

Tips to help you get the most from a visit to your doctor:

• Know the reason for your visit and what you want to happen.
• Before your visit, write down questions you want answered.
• Bring someone with you to help you ask questions and remember what your doctor tells you.
• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your doctor gives you.
• Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.
• Ask if your condition can be treated in other ways.
• Know why a test or procedure is recommended and what the results could mean.
• Know what to expect if you do not take the medicine or have the test or procedure.
• If you have a follow-up appointment, write down the date, time, and purpose of that visit.
• Know how you can contact your doctor if you have questions.