Bullous pemphigoid in a patient with suspected non-Herlitz junctional epidermolysis bullosa.

[junctional epidermolysis bullosa]

A 56 -year -old man with lifelong trauma-induced blisters , nail dystrophy and dental enamel hypoplasia presented with a new spontaneous blistering eruption . Clinicopathologically , he had evidence of both an inherited and an acquired blistering disorder : non-Herlitz junctional epidermolysis bullosa (nHJEB ) and bullous pemphigoid (BP ). HIstological examination of a skin biopsy found reduced (but not absent ) collagen XVII in nonlesional skin , in vivo bound anticollagen XVII antibodies in perilesional skin , and prominent eosinophils in perilesional and lesional skin , with subepidermal blistering . Circulating anticollagen XVII antibodies were also present . Treatment with oral corticosteroids and mycophenolate mofetil led to clinical control of the BP but had no effect on the mechanobullous blistering . Our patient is unusual in that his skin retains some labelling for collagen XVII rather than having the complete absence of immunoreactivity expected in patients with generalized nHJEB . Moreover , we were unable to identify any pathogenic mutations in the COL 17 A 1 gene encoding collagen XVII (or in other EB-associated basement membrane genes ). It is plausible that the long -term consequences of basement membrane disruption in our patient , perhaps associated with atypical inherited COL 17 A 1 pathology , might result in a conformationally altered and more immunogenic protein with the subsequent development of anticollagen XVII antibodies and BP as a secondary pathology .