The expanding spectrum of IgA pemphigus: a case report and review of the literature.

IgA pemphigus (IGAP) is a rare, distinct variant of pemphigus, currently classified, depending upon the histological features, immunofluorescence staining pattern and autoantibody profile, into two types: subcorneal pustular dermatosis (SPD) and intraepidermal neutrophilic IgA dermatosis. In a patient with a widespread blistering disease of the skin resembling SPD-type IGAP, we demonstrate the coexistence of IgA reactivity to both epidermal (desmocollins 2 and 3) and basement membrane-associated (BP180) proteins, suggesting the coexistence of atypical IGAP and linear IgA bullous dermatosis, respectively. This case, together with 20 previous reports of atypical IGAP, underscores the limitations of current classification schemes. Therefore, we suggest reclassifying these cases under the general term 'IGAP spectrum'.