Abstract: | A 72-year-old Japanese woman developed small, asymptomatic, subepidermal vesicles on the limbs, back, chest and abdomen. Immunoperoxidase staining of the lesional skin showed linear deposition of IgG, IgA and C3 along the basement membrane zone (BMZ), and indirect immunofluorescence studies revealed IgG and IgA class circulating anti-BMZ auto-antibodies in the patient's serum. Ultrastructurally, the vesicles were caused by dermo-epidermal separation at the lamina lucida, and the immune deposits were located just beneath the basal lamina in a band-like pattern. Immunoelectron microscopic observation of normal human skin incubated with the patient's serum using an organ culture system revealed that the anti-BMZ antibodies reacted with the anchoring fibrils. Administration of dapson was not effective, but betamethasone was. This case of subepidermal bullous disease is unique and cannot be classified into any existing category of bullous dermatoses. |