Gluten-free diet for dermatitis herpetiformis: the long-term effect on cutaneous, immunological and jejunal manifestations.

In 32 patients with dermatitis herpetiformis (DH) we studied the effect of gluten-free (22 patients) and gluten-reduced (10 patients) diet for periods ranging between 15 and 43 months. Variables such as cutaneous manifestations, dependence on dapsone, IgA deposits in the skin, small-bowel function, and jejunal mucosal morphology were studied. 59% of the patients on gluten-free diet could stop dapsone medication and remain symptom-free, compared with 10% on gluten-reduced diet. The time needed to achieve this therapeutic response varied from 5 to 31 months. IgA decreased in the skin to a degree which roughly paralleled the morphological normalization of the jejunal mucosa. In no patient, however, did the IgA completely disappear. It is suggested that IgA is not the main factor inducing DH symptoms, but rather a secondary phenomenon. Repeated jejunal biopsies revealed normalization of the mucosal histology in 52% of the patients on gluten-free diet, compared with none in the gluten-reduced diet group.