IgA and C3 complement in the uninvolved skin in dermatitis herpetiformis after gluten withdrawal.

IgA deposits in the skin in 53 patients with dermatitis herpetiformis (DH) have been studied in relation to treatment. In 19 patients the disorder was controlled by a gluten-freen diet (GFD) alone, in 13 patients by dapsone and GFD and in 18 by dapsone alone. In 3 patients the skin disorder became insignificant and required no treatment. Of the patients taking a GFD alone, six had been clear of skin lesions for 7 years, 5 for 3--5 years, and 8 for periods of 6 months--3 years. IgA deposits were found in all patients in an initial biopsy in a second biopsy after treatment for periods varying from 1 to 7 years. There was no difference in the quantity of IgA, as assessed by the amount of fluorescence, whether patients were controlled with a GFD alone, GFD and dapsone, dapsone alone, or in those in clinical remission. The C3 component of complement was present in the skin in 3 of the 19 patients (16%) controlled by a GFD alone, 6 of the 13 patients (46%) of those controlled by a GFD and dapsone, and in 12 of 18 (66%) of the patients taking dapsone alone, and in one of the patients in clinical remission.