Electron microscopic studies in dermatitis herpetiformis in relation to the pattern of immune deposits in the skin.

Electron microscopic studies were made in 12 cases of dermatitis herpetiformis: 6 of them with a continuous immunofluorescence line of IgA deposits at the dermo-epidermal junction, and the other 6 with granular IgA deposits in the dermal papillae. Six cases of bullous pemphigoid with a continuous immunofluorescence line of IgG deposits at the dermo-epidermal junction were examined similarly for comparison. In dermatitis herpetiformis with the continuous IgA line the ultrastructural characteristics both of dermatitis herpetiformis and bullous pemphigoid were present, even when the histological and clinical features as well as response to sulphapyridine and sulphones were typical of dermatitis herpetiformis. The ultrastructural pattern was essentially the same as in the cases with clinical and histological characteristics of the mixed dermatitis herpetiformis-bullous pemphigoid form, although in the latter there was some predominance of the characteristics of bullous pemphigoid.