Paraneoplastic pemphigoid-pemphigus? Subepidermal bullous disease with pemphigus-like direct immunofluorescence.

BACKGROUND: Paraneoplastic pemphigus is a recently described variant of pemphigus, in which classic immunologic features of pemphigus are associated with subepidermal erythema multiforme-like bullae. CASE REPORTS: Two patients with underlying malignant neoplasm had a bullous disease, which had clinical and histologic features suggestive of bullous pemphigoid while direct immunofluorescence revealed intercellular deposits of IgG and C3 throughout the malpighian layer of epidermis, a pattern usually diagnostic for pemphigus. Indirect immunofluorescence studies were negative. One mg/kg/day prednisone was enough to cure the eruption in a couple of weeks without any recurrence.
CONCLUSIONS: The disease differs from the recently reported paraneoplastic pemphigus and from other bullous diseases associating circulating pemphigus-like antibodies with clinical, histologic, and often even immunologic features of bullous pemphigoid.