Dermatitis herpetiformis (DH) is a chronic disease of the skin marked by groups of watery, itchy blisters that may resemble pimples or blisters. The ingestion of gluten (from wheat, rye, and barley) triggers an immune system response that deposits a substance, lgA (Immunoglobulin A), under the top layer of skin. IgA is present in affected as well as unaffected skin. DH is a hereditary autoimmune gluten intolerance disease linked with celiac disease. If you have DH, you always have gluten intolerance. With DH, the primary lesion is on the skin, whereas with celiac disease the lesions are in the small intestine. The degree of damage to the small intestine is often less severe or more patchy than those with celiac disease. Both diseases are permanent and symptoms/damage will occur after consuming gluten.
The lgA deposits under the skin result in eruptions of red raised patches of skin, similar to the beginning of a pimple, that can develop into small watery blisters. The itching and burning of the eruptions are severe and the urge to scratch them is intense. Scratching will further irritate the eruptions. Eruptions commonly occur on pressure points, such as around the elbows, the front of the knees, the buttocks, back, face, and scalp but can appear anywhere on the body. Eruptions are usually bilateral – occurring on both sides of the body. 60% of those diagnosed are men and the most common age at diagnosis is 15 to 40 years old. Although it is uncommon to diagnose young children with DH, we are seeing more cases of early childhood DH.
Your dermatologist will take a small biopsy of the unaffected skin very close to an eruption or eruption site. The presence of IgA deposits confirms a diagnosis of DH. Sometimes the dermatologist may also want you to have blood work for celiac disease and see a gastroenterologist.
Just as with celiac disease, strictly following a gluten-free diet for life is the only complete treatment. It may take two or more years on a gluten-free diet for the lgA deposits under the skin to clear. Your doctors may prescribe medications for immediate relief from the itching and burning eruptions. The most common medication used is Dapsone. This medication has serious side effects and requires regular monitoring by your physician. When taken to relieve the symptoms of DH, Dapsone should be taken in the smallest effective doses for as short a time as possible. Medications for DH should not be used during pregnancy.
If you use medications to relieve the itching caused from DH, but do not follow a gluten-free diet, you run the risk of also developing the intestinal problem – celiac disease and other complications.
Questions to Ask Your Doctor:
- Should I take medication for this disease?
- How long will I need to take this medicine and how will I know when to stop taking it?
- What are the side effects of the medicine?
- How often do I need to get my blood drawn to monitor this medicine’s effect on my body?
- What else can trigger DH?
Excellent, if you stay on the gluten-free diet. The severity and frequency of eruptions will decrease as you continue with the diet. Iodine can trigger eruptions in some people. However, iodine is an essential nutrient and should not be removed from the diet without a physician’s supervision.