Dermatitis herpetiformis: the skin and the gut.

Dermatitis herpetiformis is an intensely itchy, chronic, papulovesicular eruption that is usually symmetrically distributed on extensor surfaces. Histologically, it is characterized by dermal papillary collections of neutrophils and subepidermal vesicle formation. The skin has IgA deposits in areas corresponding to the earliest histopathologic change; that is, at the epidermal-dermal junction. Most patients have an associated asymptomatic gluten-sensitive enteropathy that mimics ordinary gluten-sensitive enteropathy (celiac disease) both morphologically and in its response to gluten protein. There is a marked increase in the prevalence of the major histocompatibility antigens, HLA-B8 and HLA-Dw3, and in certain B cell antigens in these patients. Although the sulfones or sulfapyridine have been the mainstay of treatment, it is now clear that the skin disease responds to strict adherence to a gluten-free diet. These findings are reviewed and from them are drawn certain conclusions as to possible pathophysiologic mechanisms involved in dermatitis herpetiformis.