Dermatitis herpetiformis (DH) is a chronic skin condition. Typically, a person with DH will have lesions with an intense itching and burning sensation. If you or someone you know has DH, treatment with a gluten free diet and/or drugs can make a big difference. The following information has been provided by the Canadian Celiac Association.
Symptoms
External symptoms are an intense burning and itching rash. The intestinal symptoms of celiac disease may or may not appear. A new, unscratched lesion is red, raised, and usually 2–5 mm in diameter with a tiny blister at the centre. If scratched, crusting appears on the surface. The burning or stinging sensation is different from a regular itch, and can often occur 8–12 hours before a lesion appears.
Causes
Genetic factors, the immune system, and sensitivity to gluten all play a role. DH and celiac disease are related autoimmune disorders that share the same genetic pathways and chromosome features. Both respond to gluten withdrawal from the diet.
Prevalence
DH occurs in 10% of patients with celiac disease. It affects males and females equally. It is more common in Caucasians than African Americans, and rare in the Japanese population. Onset is most frequently in the late second to the fourth decades of life.
Areas Affected
The most common areas are the elbows, knees, buttocks, back of the neck, scalp, and upper back. Facial and hairline lesions are less common. The rash has symmetric distribution.
Diagnosis
DH is most often associated with an abnormal mucosal lining of the small intestine, identical to changes seen in people who have celiac disease. Most people with DH have few or no bowel complaints. A small percentage have diarrhea, bloating, bulky stools, or abdominal cramps.
Diagnosis of DH can only be made by a dermatologist. The dermatologist must obtain a slight skin biopsy from uninvolved skin adjacent to blisters or erosions. If DH is confirmed, small bowel biopsies are not essential as celiac disease is known to coexist with DH.
Management
Treatment is by dapsone and a gluten free diet.
Dapsone (Avlosulfon)
The response is dramatic. Within 24–48 hours, the burning is relieved and the rash starts to disappear. The aim is to use the smallest dose possible to keep the itch and rash under control. Dapsone has no effect on the gut abnormality.
Gluten Free Diet
Elimination of all wheat, rye, barley, oats, triticale, and any parts thereof from the diet will result in:
- Improvement of skin lesions
- The gut returning to normal
- Substantial reduction in or elimination of the need for sulphones to control the skin rash
- Decreased risk of malignancy
Click here for more about the gluten free diet.
