While histologically similar, PG is distinguished by its onset during pregnancy or the postpartum period and its classic initiation as intensely itchy papules around the umbilicus.
Pemphigus features more superficial, flaccid blisters that rupture easily, unlike the tense bullae of PG.
PUPPP is the most common mimicker, but it is distinguished by starting within the abdominal striae, being composed primarily of urticarial papules (blisters are rare), and lacking the characteristic immunofluorescence findings of PG.
Simple urticaria consists of transient wheals that last for hours, whereas the urticarial plaques of PG are more persistent and evolve into vesicles and bullae.
