How should a primigravida in her third trimester manage pruritic urticarial papules and plaques of pregnancy (PUPPP) causing an itchy red rash on her abdomen?

Management of PUPPP (Pruritic Urticarial Papules and Plaques of Pregnancy)

PUPPP is a benign, self-limiting condition that requires only symptomatic treatment with topical corticosteroids and antihistamines—the critical first step is to exclude intrahepatic cholestasis of pregnancy (ICP) by checking serum bile acids, as ICP carries significant stillbirth risk and requires entirely different management. 1

Immediate Diagnostic Evaluation

Rule out ICP first before assuming the diagnosis is PUPPP:

• Order serum bile acids (non-fasting) and liver transaminases (ALT/AST) immediately in any pregnant woman with pruritus, as ICP can present with itching before bile acids rise and carries substantial fetal mortality risk 2, 1
• Bile acids >10 μmol/L confirm ICP and mandate ursodeoxycholic acid therapy plus early delivery planning 2
• Perform a detailed skin examination to identify the characteristic rash of PUPPP: erythematous urticarial papules and plaques starting within abdominal striae and spreading to proximal thighs 1, 3, 4
• ICP typically presents with pruritus affecting palms and soles, worsening at night, without a primary rash (only excoriations from scratching) 2, 5

Clinical Features That Confirm PUPPP

Once bile acids are normal, PUPPP diagnosis is based on:

• Pruritic urticarial papules and plaques beginning on the abdomen within striae distensae, spreading to proximal thighs and extremities 3, 4
• Onset typically in third trimester (89% of cases), most commonly in primigravidas (72%) 4
• Sparing of the periumbilical area is characteristic (unlike ICP which has no rash pattern) 3, 6
• Face, palms, and soles are usually spared, though rare cases involve these areas 6
• Multiple gestation pregnancy is present in 50% of cases 4

Treatment Algorithm for PUPPP

First-line therapy:

• Topical corticosteroids (medium to high potency) applied twice daily to affected areas are the mainstay of treatment 3, 4
• Fluticasone propionate 0.05% lotion (class 5, low-medium potency) applied twice daily can achieve complete resolution within one week and has a benign safety profile in pregnancy 7
• Oral antihistamines (hydroxyzine or fexofenadine) for pruritus control, particularly at night 4, 8
• Emollients and oatmeal baths provide additional symptomatic relief 8

Second-line therapy if first-line fails:

• Systemic corticosteroids (oral prednisone) are reserved for severe, refractory cases that do not respond to topical therapy within 2-3 days 3, 8
• Most cases resolve with conservative management within an average of 3 weeks 4

Reassurance and Prognosis

• PUPPP has excellent maternal and fetal prognosis with no adverse pregnancy outcomes 3, 4
• Lesions resolve spontaneously after delivery (usually within days to weeks) with no scarring or pigmentary changes 3
• Recurrence in subsequent pregnancies is uncommon 6
• The newborn is unaffected and does not develop skin lesions 3

Critical Pitfall to Avoid

Never assume pruritus in pregnancy is benign PUPPP without checking bile acids first—ICP can present with itching before laboratory abnormalities develop, and missing this diagnosis risks sudden stillbirth even with reassuring fetal testing 2, 1. If initial bile acids are normal but pruritus persists or worsens, repeat testing in 1-2 weeks, as ICP can develop later in pregnancy 1.

When to Escalate Care

• If bile acids are elevated (>10 μmol/L), immediately initiate ursodeoxycholic acid 10-15 mg/kg/day and plan delivery timing based on bile acid levels 2
• If vesicles or bullae develop, consider pemphigoid gestationis and obtain dermatology consultation with skin biopsy 6
• If pruritus persists beyond 6 weeks postpartum, refer to hepatology to evaluate for underlying chronic liver disease 2