Pruritic urticarial papules and plaques of pregnancy
A pregnancy-specific rash that resolves without long-term risk.
Pruritic urticarial papules and plaques of pregnancy (PUPPP), also called polymorphic eruption of pregnancy (PEP), is a chronic hives-like rash that occurs in about 1 in every 160 pregnancies. It is one of several skin conditions specific to pregnancy and presents no long-term risk for either the woman or fetus, despite frequently severe itching.
Quick Facts
- Incidence
- 1 in every 160 pregnancies (0.625%)
- Onset
- Most commonly during the third trimester; 15% of cases begin immediately after delivery
- Blood type association
- In one study of 18 cases in Lebanon, all 18 mothers had Rh-positive blood type
- Ivf association
- In the same study, 50% of pregnancies were the result of in vitro fertilization (global IVF rate 2-5%)
Facts from the source article.
Signs and symptoms
The rash typically begins within stretch marks on the abdomen, appearing red, itchy, and raised, with notable swelling. Over time, individual segments may join into larger plaques, and the surrounding skin often appears white in a halo pattern. The rash can spread to the trunk, arms, legs, feet, chest, and neck, but rarely involves the face, palms, or soles. As the condition progresses, widespread erythema and eczematous patches of inflamed, rough, cracked skin may develop. Tiny vesicles have been reported in some cases but are less common and appear later. Symptoms most often begin in the third trimester, though 15% of affected women report onset immediately after delivery. The umbilicus is typically spared, and lesions on or above the breasts are rare. The itching is often severe and can significantly impair sleep quality.
Cause
The exact cause is unknown and may vary between individuals. Hypotheses include hormonal alterations, damage to connective tissue during pregnancy, and autoimmune mechanisms, but evidence for these is inconclusive. The condition is most frequent in first pregnancies, in the third trimester, and is more likely with multiple gestations (triplets more than twins or singletons). Rapid stretching of the abdominal wall is thought to trigger an inflammatory reaction due to exposure of collagen. Hormonal changes, particularly increased progesterone and estradiol levels in multiple gestations, may contribute, though evidence for a hormonal role is weak. Associations with hypertension and induction of labour have been noted, but no differences in pregnancy outcomes for mothers or babies have been observed.
Diagnosis
PUPPP is a diagnosis of exclusion, requiring laboratory testing to rule out other dermatoses. Tests may include complete blood count, comprehensive metabolic panel, liver function tests, serum human choriogonadotropin, serum cortisol, and immunofluorescence studies of serum or biopsy specimens to exclude pemphigoid gestationis. A common misdiagnosis is urticarial pemphigoid gestationis, which typically involves the umbilicus and appears earlier in gestation. Eczema is distinguished by a personal or family history of atopy and lesions on flexural areas. A 3- or 4-mm punch biopsy may be used to exclude herpes gestationis, though biopsy features are consistent with PUPPP without being pathognomonic. Direct immunofluorescence of perilesional skin can aid in excluding herpes gestationis.
Treatment
Women experiencing symptoms should consult a primary care physician for referral to a dermatologist and should not self-treat. In most cases, PUPPP resolves within days to weeks of onset or spontaneously within a week of delivery, though some women experience symptoms long into the postpartum period. Intramuscular injection of autologous whole blood after childbirth has been suggested as an alternative treatment. Antihistamine tablets may provide relief from itching and improve sleep, though they are generally less effective than corticosteroids. First-generation antihistamines such as chlorpheniramine are considered safe in pregnancy, and second-generation antihistamines like loratadine and cetirizine may also be used. High-potency topical steroids (Class I or II) are the mainstay of treatment, ideally tapered after 7 days; oral corticosteroids are reserved for severe cases, with caution regarding risks to the fetus. Use of over 300 grams of high-potency topical corticosteroids during pregnancy may increase the risk of low birth weight. In persistent cases, induction of labour at term (37 weeks) has been performed.
More in Pathology of Pregnancy, Childbirth and the Puerperium
Spotted an error? Know more?
Reader corrections go straight into our review queue. Suggest an edit · How this site is sourced