[Mixed bullous diseases].
As mixed bullous diseases are presented the intermediate forms between bullous pemphigoid (BP) and dermatitis herpetiformis (DH) with clinical and histologic features of both diseases, and with linear deposits composed exclusively or mainly of IgA at the basement membrane zone in the direct immunofluorescence test. This type of mixed bullous disease is more common in children (juvenile DH), although typical DH and BP cases as in adults occur also in childhood. Also herpes gestationis seems to be related to mixed bullous diseases with prevalence of immunologic phenomena characteristic of BP, although its IF pattern may be regarded as diagnostic (usually absence of circulating and in vivo bound antibasement antibodies, and presence of some complement components at the dermal-epidermal juncti0n). Especially controversial is in this group a variety of pemphigus with clinical features of DH, and good response to sulfapyridine of some cases, presenting acantholysis and immunological phenomena specific for pemphigus. For this form of pemphigus the term herpetiform pemphigus has been proposed. In the group of mixed bullous diseases should also be included cases of coexistence-in different periods, or concomitantly-of pemphigus and BP.