The ultrastructural localization of IgA in skin of a patient with mixed form of dermatitis herpetiformis and bullous pemphigoid.

A case with mixed features of dermatitis herpetiformis and bullous pemphigoid was investigated by immuno-electron microscopy. There were clinical, histological, and ultrastructural characteristics of both diseases, the response to sulfapyridine was dramatic at the beginning, but intestinal lesions were absent. Direct immunofluorescence tests were made 6 times in the 4 year period and demonstrated in all biopsies exclusively linear IgA deposits. The IgA deposits were shown to occupy the entire lamina lucida and to adhere to the basal cell membranes and lamina densa, very much like IgG deposits in bullous pemphigoid. Antibodies against the basement membrane zone could not be demonstrated in the serum.