Neonatal pemphigus vulgaris: IgG4 autoantibodies to desmoglein 3 induce skin blisters in newborns.

We report a case of neonatal pemphigus vulgaris presenting with skin lesions on the head, genital area, and right foot. Pemphigus vulgaris was diagnosed by the presence of circulating autoantibodies predominantly of the IgG4 subtype by indirect immunofluorescence microscopy and by enzyme-linked immunosorbent assay using recombinant desmoglein 3. This case demonstrates the pathogenic relevance of IgG4 autoantibodies to desmoglein 3 in the skin of neonates.