title: Bullous pemphigoid in a patient with suspected non-Herlitz  junctional epidermolysis bullosa.
abstract: 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 COL17A1 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 COL17A1 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.
authors.affiliation: St John's Institute of Dermatology, Guys and St Thomas' NHS Foundation Trust and King's College London (Guy's Campus), London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Pérez
authors.forename: N
authors.initials: N
authors.lastname: Almaani
authors.forename: C M
authors.initials: CM
authors.lastname: Stefanato
authors.forename: B
authors.initials: B
authors.lastname: BhogaL
authors.forename: R W
authors.initials: RW
authors.lastname: Groves
authors.forename: J E
authors.initials: JE
authors.lastname: Mellerio
authors.forename: J A
authors.initials: JA
authors.lastname: McGrath
mesh_terms: D001324:Autoantigens / Q000378:metabolism*; D001768:Blister / Q000150:complications; D001932:Brain Neoplasms / Q000175:diagnosis; D003744:Dental Enamel Hypoplasia / Q000150:complications; D004804:Eosinophils / Q000473:pathology; D016109:Epidermolysis Bullosa, Junctional / Q000150:complications* / Q000188:drug therapy / Q000473:pathology; D017809:Fatal Outcome; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009173:Mycophenolic Acid / Q000031:analogs & derivatives / Q000627:therapeutic use; D009260:Nail Diseases / Q000150:complications; D024041:Non-Fibrillar Collagens / Q000378:metabolism*; D010391:Pemphigoid, Bullous / Q000150:complications* / Q000188:drug therapy / Q000473:pathology; D011239:Prednisolone / Q000627:therapeutic use; D000097805:Collagen Type XVII
chemical_list: D001324:Autoantigens; D005938:Glucocorticoids; D007166:Immunosuppressive Agents; D009173:Mycophenolic Acid; D024041:Non-Fibrillar Collagens; D011239:Prednisolone; D000097805:Collagen Type XVII