BACKGOUND:

Pruritic urticarial papules and plaques of pregnancy is a benign dermatosis of unknown etiology that appears in primiparous women in the last trimester of pregnancy. Associated risk factors are abdominal enlargement, polyhydramnios, macrosomic fetus, and maternal weight gain.

OBJECTIVE:

To report the uncommon case of a primiparous female patient with a dermatosis that developed post partum.

CLINICAL CASE:

A 28-year-old patient, who attended the consultation on the ninth day of the puerperium due to an intensely pruritic dermatosis, disseminated to the trunk and extremities, of one week's evolution. Physical examination revealed: bilateral and asymmetric dermatosis, predominantly affecting the abdomen, trunk, chest, and pelvis; polymorphous in appearance, composed of hyperchromic, erythematous-violaceous macules, some frankly urticarial, others with a bull's-eye appearance and others even with superficial micro-vesicles of different sizes, confluent with well-defined borders, extremely pruritic. The histopathological study reported: irregular acanthosis, with slight spongiosis, formation of intra-epidermal vesicles and inflammatory infiltrate composed of lymphocytes and numerous eosinophils in the superficial dermis. He established the diagnosis of polymorphous erythema of pregnancy, with manifestation during the puerperium. Treatment consisted of general skin care measures; oral cetirizine and topical desonide (in lesions), with complete healing in 15 days.

CONCLUSIONS:

The prognosis of patients with polymorphic erythema of pregnancy is good, with no repercussions on maternal and neonatal morbidity or mortality. It is important to identify polymorphous erythema of pregnancy during the puerperium, in order to provide timely treatment.