The biopsy revealed a perivascular infiltrate of mononuclear cells and eosinophils in the superficial dermis. Numerous eosinophils were present intravascularly. The epidermis was hyperplastic in a psoriasiform pattern with mild spongiosis and extensive infiltration by eosinophils (Figure 2). Direct immunofluorescence studies demonstrated focal staining on the cell surface of keratinocytes in the lower two-thirds of the epidermis for IgG and C3. No immunoreactants were detected for IgM, IgA, or fibrin (Figure 3). Findings from indirect immunofluorescence using monkey esophagus as the substrate showed antibodies against intercellular spaces at a titer of 1:40. In enzyme-linked immunosorbent assays, anti–desmoglein 3 (anti-Dsg3) antibody level was elevated at 77 U/mL and anti-Dsg1 antibodies were negative.