Polymorphic eruption of pregnancy (PEP), a specific dermatosis of pregnancy also known as pruritic urticarial papules and plaques of pregnancy (PUPPP), is a benign, self-limited skin disorder. Key features include an increased prevalence in primigravidas, onset in the third trimester, remission near the time of delivery, and association with multiple gestation pregnancy. The clinical features are crucial to diagnosis. Histopathology is nonspecific, and immunofluorescence studies help differentiate PEP from pemphigoid gestationis. The pathogenesis of PEP remains elusive, and relevant theories are reviewed. There are no associated maternal or fetal risks, and treatment is largely symptomatic.