Dermatitis Herpetiformis and Celiac
Dermatitis Herpetiformis (DH) is a severe, itchy, blistering skin manifestation of celiac disease that is genetically determined and is not contagious. The name, dermatitis herpetiformis, is a descriptive name and is not related to either dermatitis or herpes, but is a specific chronic skin condition. The rash may occur in the form of small lumps, like insect bites and in some cases form fluid filled blisters. These small blisters are called vesicles. However the rash may appear hive-like, persisting in one area. DH can flare and subside even without treatment.
The rash usually occurs on the elbows, knees, and buttocks. When the rash subsides, which it often does spontaneously, it may leave brown pigmentation or pale areas, where pigmention is lost.
DH affects males more often than females and generally presents in adult life (20-55). It is uncommon to see DH in children, but it can occur. Not all people with celiac disease develop dermatitis herpetiformis. Unlike other forms of celiac disease, the range of intestinal abnormalities in DH is highly variable, from minimal to severe. Only about 20 percent of people with DH have intestinal symptoms of celiac disease. However biopsies show that 80% have some degree of villous atrophy. Recent findings confirm that all patients with DH will display villous atrophy if a high gluten diet is maintained. There is a small subset of patients with celiac disease who develop DH even though they have been on a strict gluten free diet. Like celiac disease, it is not known why the condition develops at a particular time.
Like celiac disease, DH is treated with a lifelong gluten-free diet. It may take about six months to achieve moderate improvement in the skin condition and up to two years or more to achieve total control by diet alone, meaning that the skin response is much slower compared to the healing of the intestines with celiac disease.
The rash symptoms can be controlled with medications such as dapsone. However, dapsone does not treat the intestinal condition, meaning that people with DH should also maintain a gluten-free diet.
The majority of patients with DH do not display any symptoms of bowel disease despite the fact that their bowel biopsies are abnormal. They are said to have asymptomatic bowel disease. Both DH and celiac patients not on a gluten-free diet have a small, but statistically higher risk of developing lymphoma of the small intestine, particularly when the condition has been present for many years.