Concomitant immunohistochemical characteristics of pemphigoid and dermatitis herpetiformis in a patient with atypical bullous dermatosis.

We report a patient who developed a vesiculobullous eruption which clinically and histologically showed features of pemphigoid and dermatitis herpetiformis, responded to prednisone but doubtfully to dapsone, and demonstrated 'classical' immunopathologic characteristics of phemphigoid and dermatitis herpetiformis. Peribullous and unaffected skin featured deposition of IgG and C3c in a homogeneous-linear pattern at the epidermal basement membrane, while the unaffected skin demonstrated concomitantly granular IgA deposits in the dermal papillae. Circulating IgG class anti-basement membrane antibody was found in a titre of 1:80 when using guinea-pig oesophagus, and of 1:320 when using human oral mucosa as antigenic substrate. Our findings add another piece to the puzzle that continues to stimulate discussion among dermatologists as how to classify patients with overlapping features of pemphigoid and dermatitis herpetiformis. (Received February 18, 1983.)