Polymorphic eruption of pregnancy, also known as 'PUPPP' (Pruritic Urticated Papules and Plaques of Pregnancy). With an incidence of about 1: 250 in first pregnancies, PUPPP arises late in the third trimester and is more frequent with twins or if the abdomen is excessively stretched. Itchy red papules and plaques start in the striae distensae and may progress to affect trunk and limbs.

None. This is in contrast to the rare bullous disease, pemphigoid gestationis, which may affect the fetus. Pemphigoid gestationis is due to autoantitbodies against the basement membrane and commences earlier in pregnancy.

PUPPP will resolve within a week or so of delivery of the baby and is entirely benign. However, PUPPP results in severe pruritus, which may disturb sleep. If necessary, the following may be used to relieve the itch: antipruritic emollient lotions, high potency topical steroid creams and conventional oral antihistamines such as promethazine or diphenhydramine. Oral corticosteroids should be reserved for severe refractory cases only.