Neonatal pemphigus vulgaris with extensive mucocutaneous lesions from a mother with oral pemphigus vulgaris.

The clinical phenotype of pemphigus is well explained by the combination of desmoglein (Dsg) 1 and Dsg3 distribution pattern and antiDsg autoantibody profile (Dsg compensation theory). It has been reported that neonatal skin has a similar Dsg distribution pattern to adult mucosal epithelia. We describe a newborn girl with mucocutaneous pemphigus vulgaris (PV) from a mother with mucosal dominant PV. The mother had had painful oral erosions for at least 7 months. Histopathological examination and direct and indirect immunofluorescence studies confirmed the diagnosis of PV and neonatal PV in the mother and daughter, respectively. The mother had a high titre of anti-Dsg3 IgG and a low titre of antiDsg1 IgG, while the neonate had only a high titre of anti-Dsg3 IgG, but no detectable antiDsg1 IgG. AntiDsg3 IgG, which caused the oral dominant phenotype in the mother, induced extensive oral as well as cutaneous lesions in the neonate. Our case provides clinical evidence for the Dsg compensation theory in neonatal PV.