Intraepidermal IgA pustulosis.

Since 1979, 29 patients with intraepidermal IgA detected by direct immunofluorescence have been reported. A review shows that they have a cutaneous disease clinically similar to subcorneal pustular dermatosis, or Sneddon-Wilkinson disease. The pustules may be subcorneal or intraepidermal. IgA deposits are usually found on the intercellular substance of the epidermis, although a subcorneal linear pattern has also been described. Circulating IgA class antiepidermal autoantibodies may be present. The disease usually responds to dapsone. In six cases, a monoclonal IgA gammopathy was present. Although little is known about the pathogenesis of this condition, we believe that it represents a distinct entity among the group of the neutrophilic dermatoses. Various diagnostic terms have been used; we propose intraepidermal IgA pustulosis.