Dermatitis herpetiformis (DH) is a chronic, severe, intensely itchy, blistering skin manifestation of gluten sensitive enteropathy, commonly known as
celiac disease.

Not all people with celiac disease develop dermatitis herpetiformis. Dermatitis herpetiformis affects 15 to 25 percent of people with celiac disease. The rash usually occurs on the elbows, knees, and buttocks.

Unlike other forms of celiac disease, the range of intestinal abnormalities in dermatitis herpetiformis (DH) is highly variable, from minimal to severe. Only about 20 percent of people with dermatitis herpetiformis (DH) have intestinal symptoms of celiac disease.

Dermatitis herpetiformis is found mainly in adults and is more common in men and people of northern European descent.

Symptoms of Dermatitis Herpetiformis

Dermatitis herpetiformis is characterized by small, clustered papules and vesicles that erupt symmetrically on the elbows, knees, buttocks, back, or scalp. Men may also have oral or genital lesions. A burning sensation may precede lesion formation.

Causes of Dermatitis Herpetiformis

Dermatitis herpetiformis is caused by the deposit of immunoglobulin A (IgA) in the skin, which triggers further immunologic reactions resulting in lesion formation. Dermatitis herpetiformis is an external manifestation of an abnormal immune response to gluten, in which IgA antibodies form against the skin antigen epidermal transglutaminase.

Diagnosis of Dermatitis Herpetiformis

To diagnose dermatitis herpetiformis (DH), a doctor will test a person’s blood for autoantibodies related to celiac disease and will biopsy the person’s skin.

If the antibody tests are positive and the skin biopsy has the typical findings of dermatitis herpetiformis (DH), a person does not need to have an intestinal biopsy.

Treatment of Dermatitis Herpetiformis

Both the skin disease and the intestinal disease respond to a gluten-free diet and recur if gluten is added back into the diet.

The rash symptoms can be controlled with medications such as dapsone (4′,4′diamino-diphenylsuphone), a sulfone. Dapsone does not treat the intestinal condition and people with dermatitis herpetiformis (DH) should also maintain a gluten-free diet.

Source: digestive.niddk.nih.gov