IgG/IgA pemphigus reactive with desmoglein 1 with additional undetermined reactivity with epidermal basement membrane zone.

IgG/IgA pemphigus is an extremely rare subset of pemphigus, showing anti-keratinocyte cell surface antibodies of both IgG and IgA classes. Herein, we describe a unique case of IgG/IgA pemphigus with clinical features of edematous erythema and peripheral vesiculopustules. Histopathology showed the presence of subcorneal pustules and acantholytic blisters in the mid-epidermis with neutrophilic infiltration and eosinophilic spongiosis. Direct immunofluorescence of perilesional skin showed both IgG and IgA deposits to keratinocyte cell surfaces and unusual granular deposits of IgG, IgM, and C3 along basement membrane zone. On enzyme linked immunosorbent assay , the auto-antibodies were found to be reactive to desmoglein 1 antigen. Various clinical, histopathological, and immunological findings in our case overlapped with the features of IgA pemphigus, pemphigus herpetiformis, and pemphigus foliaceus. These findings indicate that IgG/IgA pemphigus may be a transitional form between IgA pemphigus and pemphigus herpetiformis, and thus provides insight into the pathogenicity of this rare disorder.