Herpes gestationis: fine structural pattern of immunoglobulin deposits in the skin in vivo.

IgG and C3 deposits were observed in the basement membrane zone in a case with herpes gestationis. In addition, circulating IgG anti-basement membrane antibodies were found. Electron microscopic immunocytochemical investigations, performed with a peroxidase-antiperoxidase sandwich technique, revealed the in vivo-bound IgG to be localized at the epidermal basal lamina and to exhibit a distribution pattern which is identical to that reported for bullous pemphigoid.