Herpetiform pemphigus without anti-desmoglein 1/3 autoantibodies.

We report a patient with herpetiform pemphigus who was negative for autoantibodies to desmoglein (Dsg)1 or 3. He had erythemas with vesicles lining the margins on the trunk and extremities. Histopathology revealed intraepidermal blister with prominent eosinophil infiltration. Direct and indirect immunofluorescence demonstrated the presence of depositing and circulating immunoglobulin (Ig)G autoantibodies, but no IgA antibodies, to keratinocyte cell surface. Nonetheless, neither anti-Dsg1 nor Dsg3 antibodies were detected by enzyme-linked immunosorbent assay. Immunoblotting using human epidermal extracts also showed no reactivity with known intraepidermal or epidermal-dermal junctional substances. Immunoelectronmicroscopy revealed the reactivity on the portion of keratinocyte cell surface but not on the desmosomes. This case suggests that non-desmoglein antigen on keratinocyte cell surface can be targeted in some patients with this unusual variant of pemphigus.