What is Polymorphic eruption of pregnancy?

Polymorphic eruption of pregnancy, also known as Pruritic Urticarial Papules and Plaques of Pregnancy (PUPPP), is a benign dermatological condition characterized by an intensely pruritic, erythematous rash. It typically manifests in the third trimester of pregnancy, initially presenting in the striae distensae (stretch marks) of the abdomen, and often resolves spontaneously following delivery.

Causes of Polymorphic eruption of pregnancy

The exact cause of Polymorphic Eruption of Pregnancy is not fully understood, although it is believed to be triggered by skin stretching, particularly on the abdomen, which induces an immune response due to connective tissue damage. The condition occurs in about 1 in 160 pregnancies, with a higher incidence in primigravid women. It is more common in women with white skin, and the risk increases with excessive weight gain or multiple gestations. Additionally, carrying a male fetus is associated with a higher risk than carrying a female fetus

Clinical features of Polymorphic eruption of pregnancy

Polymorphic eruption of pregnancy (PEP) typically manifests during the third trimester, often in the final weeks of gestation. Approximately 15% of affected women report the onset of symptoms postpartum. The condition initially presents with small, pink papules, predominantly located within the stretch marks around the umbilicus, frequently accompanied by a pale halo surrounding each lesion. Over time, these papules merge to form large, erythematous, urticated plaques, with occasional vesicular lesions. The rash progressively extends from the abdomen to the buttocks and thighs and may occasionally involve the arms and legs; however, lesions are rarely seen on or above the breasts. PEP is characteristically pruritic, with intense itching that often disrupts sleep.

Diagnosis of Polymorphic eruption of pregnancy

Polymorphic eruption of pregnancy is typically diagnosed based on clinical history and characteristic findings. There are no definitive diagnostic tests for this condition, and skin biopsy results are generally nonspecific.

Treatment of Polymorphic eruption of pregnancy

Polymorphic eruption of pregnancy does not have a curative treatment. Symptomatic management typically includes:

Emollients
Topical corticosteroids: Applied sparingly once or twice daily to alleviate pruritus and erythema.
Systemic corticosteroids: A short course (e.g., prednisone) may be considered in severe cases.
Antihistamines: Oral antihistamines are generally safe in late pregnancy.

Prognosis of Polymorphic eruption of pregnancy

Polymorphic eruption of pregnancy typically persists until delivery and generally resolves within 4 to 6 weeks postpartum. However, in rare instances, the condition may persist beyond this period

Recurrence of polymorphic eruption of pregnancy is rare; when it does occur, it is typically less severe.

Written by:

Atheer Alhuthaili, Medical Intern.

Revised by:

Naif Alshehri, Medical Intern.

References:

DermNet.

Medscape