IgA pemphigus foliaceus. Report of two cases and a review of the literature

The cases of two patients with vesiculobullous lesions were diagnosed clinically and histopathologically as pemphigus foliaceus; unexpectedly, both revealed intercellular IgA, but not IgG, in the upper epidermis by direct immunofluorescence. Such histologic and immunofluorescence findings have been reported in eight other cases. In our cases no circulating IgA or IgG intercellular antibodies could be detected; in four of eight other reported cases IgA antibodies showed intercellular staining like that of pemphigus antibodies. Subcorneal acantholytic lesions occurred in both our cases; of the other cases reported, five had essentially identical histopathologic findings. The clinical and histopathologic features of pemphigus, as well as the recent findings of circulating IgA intercellular antibodies alone or with IgG antibodies, appear to place this disease into the spectrum of pemphigus. The 10 IgA pemphigus cases reported to date fall into one of two groups, the IgA pemphigus foliaceus (including our two cases) and IgA pemphigus of the intraepidermal neutrophilic type, which seems to be less common.