Pemphigoid gestationis (herpes gestationis)
This is pemphigoid occurring in pregnancy, or in the presence of a hydatidiform mole or a choriocarcinoma. As in pemphigoid, most patients have linear deposits of C3 along the basement membrane zone (Fig. 9.5), although IgG is detected less often. The condition usually remits after the birth but may return in future pregnancies. It is not caused by a herpes virus: the name herpes gestationis should be discarded now so that the disease is not confused with herpes genitalis. Treatment is with systemic steroids. Oral contracept-ives should be avoided.