Herpes gestationis in mother and erythemato-pustulous rash in the newborn with positive direct immunofluorescence. A transfer of the disease?

A 24-year-old secundigravida presented at 38 weeks of amenorrhea with typical cutaneous lesions of herpes gestationis. The newborn developed a skin rash 3 days after birth. The rash clinically resembled erythema toxicum neonatorum with dermal infiltrate of lymphocytes and eosinophilic polymorphonuclear cells forming a few intraepidermal pustules. The complement-binding antibody test for herpes gestationis factor was negative, but direct immunofluorescence study on this biopsy demonstrated a linear deposit of IgG and complement on the basement membrane zone. The possible transmission of the disease to the newborn is discussed.