[Bullous pemphigoid with pemphigus type antibodies in vivo. 2 cases]

Pemphigus vulgaris, whether of the vulgaris or foliaceus variety, and bullous pemphigoid (BP) are two groups of auto-immune bullous diseases which in most cases can easily be differentiated on the basis of clinical, histological and, mainly, immunopathological data. Like cicatricial pemphigoid, BP may be accompanied with circulating pemphigus-like antibodies (PLA) which are not detected in vivo by direct immunofluorescence (IF). However, a true pemphigus-BP association, as reported first by Chorzelski et al., is exceptional. Two cases of BP immunolabelled with pemphigus-like antibodies at direct IF are reported, raising a discussion on this particular association. The first case concerns a 62-year old man presenting with extensive psoriasis treated with salicylated vaseline and topical corticosteroids. The patients was admitted for a disseminated, symmetrical and pruriginous bullous eruption made up of tense bullae on healthy and psoriatic skin or on an urticarial background, without Nikolsky's sign. Pathological examination of a recent bulla showed subepidermal detachment without acantholysis. Direct cutaneous IF revealed linear labelling of the basement membrane zone with IgG, C3 and C1q, and labelling of the inter-cellular substance of the epidermis with IgG. Indirect IF on O+ human skin demonstrated antibodies of the pemphigoid type (1/128) and of the pemphigus type (1/64). Standard laboratory examinations only showed moderate blood eosinophilia (950/mm3) and a rise in total IgE. Under systemic corticosteroid therapy (prednisone 1 mg/kg/day) and azathioprine (2 mg/kg/day) the bullae rapidly disappeared.(ABSTRACT TRUNCATED AT 250 WORDS)