Dermatitis herpetiformis is an extremely itchy rash made of bumps and blisters. The rash is chronic, which means it continues over a long period of time.

Dermatitis herpetiformis usually begins in persons age 20 and older, although children may sometimes be affected. It is seen in both men and women.

The cause is unknown. However, dermatitis herpetiformis is frequently linked to gluten sensitivity (celiac sprue disease) in the small bowel.

Dermatitis herpetiformis is usually extremely itchy. The bumps or blisters usually appear on the elbows, knees, back, and buttocks. In most cases, the rash is the same size and shape on both sides. Symptoms of dermatitis herpetiformis tend to come and go.

A skin biopsy and direct immunofluorescence test of the skin are performed in most cases. Your doctor may also recommend a biopsy of the intestines.

Dapsone, an antibiotic, may help most patients.

A strict gluten-free diet will also be recommended to help control the disease. Sticking to this diet may remove the need for medications and prevent later complications.

The disease may be well controlled with treatment. Without treatment, the risk of intestinal cancer may be significant.

Thyroid disease may be found in many patients with dermatitis herpetiformis. Patients are also more likely to develop certain cancers of the intestines.

Call your health care provider if you have a rash that continues despite home treatment.

There is no known prevention of this disease. Persons with this condition may be able to prevent complications by avoiding foods that contain gluten.

Habif TP. Clinical Dermatology. 4th ed. St. Louis, Mo: Mosby; 2004.

McPherson RA, Pincus MR. Henry's Clinical Diagnosis and Management by Laboratory Methods. 21st ed. St. Louis, Mo: WB Saunders; 2006.