Dermatitis Herpetiformis

Natalia Plotnikova, BS; Jami L. Miller, MD

Disclosures

Skin Therapy Letter. 2013;18(3) 

In This Article

Therapy

A strict GFD is the first-line treatment in DH and the only therapy that can improve the intestinal disease. This involves avoidance of wheat, barley, rye, and their byproducts. The degree to which the patient's condition improves is inversely correlated with the amount of gluten consumed.[22] However, it generally takes several months to years for the cutaneous symptoms to improve if the disease is treated by dietary means alone.[23] GFD was also shown to reduce the incidence of small bowel lymphoma. About 12 to 18% of patients experience long-term remission and in this cohort the GFD may be discontinued.[24,25]

Dapsone is the major medical treatment for DH. Compared to GFD, dapsone induces an acute response in DH eruption as early as 24 hours. Dapsone dose ranges from 25 to 400 mg, with the average dose of 100 mg per day.[26] While dapsone inhibits neutrophil chemotaxis and IL-8 release, it does not seem to affect cutaneous complement deposition.[27,28] Glucose-6-phosphate dehydrogenase (G6PD) levels should be checked in all patients prior to initiating dapsone, since the medication cannot be used in individuals with this enzyme deficiency due to severe hemolytic anemia. Some degree of hemolytic anemia and methemoglobinemia occurs in most people taking dapsone but generally does not require specific treatment. Ascorbic acid, vitamin E and cimetidine at 400 mg three times daily were shown to counteract drug-induced methemoglobinemia.[29,30] Other side effects of dapsone include leukopenia, agranulocytosis, dapsone hypersensitivity syndrome, cutaneous drug reactions, liver abnormalities, peripheral neuropathy, nephrotic syndrome and pulmonary abnormalities.[31] Baseline complete blood count (CBC) with differential, renal and liver function tests, and urinalysis should be checked.[5] Afterwards, monitoring of CBC is recommended to be performed weekly for 1 month, then every other week for 1 month and later every 3 to 4 months.[26] The therapy should be discontinued if white blood cell count falls below 4000 cells/mm3.[7] Signs of peripheral motor neuropathy should be evaluated on physical exam. Liver and renal function tests should be checked every 3 months or if symptoms of dysfunction are apparent.[26] Most often, a combined therapy of GFD and dapsone is needed to address both acute cutaneous manifestations and provide long-term control, with gradual reduction in dose or complete weaning of dapsone over a few months. Provided strict compliance with GFD, 85% of patients are able to reduce their dapsone dose by half or more, or even discontinue it completely.[7]

Other sulfones, although less effective then dapsone, can be used in patients with DH.[32] Sulfasalazine is the most readily available medication of this class in the United States, with sulfapyridine being only accessible at certain locations.[26] Doses of 2 to 4 g/day of sulfasalazine or 1 to 2 g/day of sulfapyridine are used.[26]

If not controlled adequately by antihistamines, oral steroids, while not an effective chronic therapy, could help alleviate intense pruritus in acute flares.[33] There are case reports indicating a positive response to cyclosporine, colchicines, heparin, tetracycline, and nicotinamide.[34–36] Other immunosuppressants, such as azathioprine, are rarely needed.

Overall, a multidisciplinary approach is beneficial with involvement of a dermatologist and dietician, as well as potentially a gastroenterologist and rheumatologist. Patients can also be directed to the Celiac Disease Foundation and the Gluten Intolerance Group for additional support and dietary advice.

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