His viral culture was negative for VZV and HSV Histopathologic examination revealed an intraepidermal vesicle
containing balloon cells and multinucleated epithelial cells with reticular degeneration and a dense infiltration of lymphocytes, histiocytes, and neutrophils around the vesicle and superficial blood vessels.
Histopathological examination of intact vesicle showed an intraepidermal vesicle
with few neutrophils.
Histologic examination of an umblicated vesicle taken from the forearm showed intraepidermal vesicle
and pustule formation with ballooning degeneration in the periphery.
In the ulcerative variant of PG, there is massive dermal-epidermal neutrophilic infiltrate with suppuration/abscess formation; in pustular PG, a perifollicular neutrophilic infiltrate with subcorneal pustule formation; the bullous variant shows a neutrophilic infiltrate with intraepidermal vesicle
Electron microscopy may show atypical intraepidermal vesicles
at 16th weeks gestation.
The lesion is characterized by intraepidermal vesicles
with acantholysis and an intact basal layer.