Itch in pregnancy
Exam Tips
- High-yield discriminator: itch without primary rash in late pregnancy should trigger urgent bile acids and LFTs to rule out obstetric cholestasis.
- PUPPP classically starts in abdominal striae with umbilical sparing; pemphigoid gestationis often involves the umbilical area and can blister.
- For OSCEs, always state maternal symptom control plus fetal risk assessment/obstetric planning when discussing cholestasis management.
- Remember postpartum course: polymorphic and atopic eruptions usually settle, while pemphigoid may flare at delivery before gradual resolution.
- Image spotter prep: review atlas figures of striae-centered urticated plaques (PUPPP) and tense bullae on erythematous base (pemphigoid gestationis).
Definition
Itch in pregnancy (pruritus gravidarum spectrum) is an unpleasant sensation causing a persistent urge to scratch during gestation, and may arise from pregnancy-specific dermatoses or coincidental non-obstetric disease. Clinically, the key distinction is between itch without a primary rash (classically obstetric cholestasis/intrahepatic cholestasis of pregnancy) and itch with a primary eruption (for example polymorphic eruption of pregnancy, atopic eruption of pregnancy, or pemphigoid gestationis), because maternal and fetal risk differs substantially.
Pathophysiology
Mechanisms depend on the underlying diagnosis. In obstetric cholestasis, impaired hepatobiliary transport in genetically/hormonally susceptible women leads to raised bile acids and other pruritogens (including lysophosphatidic acid pathways), producing intense itch often without visible primary skin lesions; fetal risk is linked to high maternal bile acids. Polymorphic eruption of pregnancy (PUPPP) is thought to be an inflammatory reaction related to abdominal skin stretching and immune activation, while atopic eruption reflects pregnancy immune shift toward Th2-dominant responses that unmask/worsen eczematous disease. Pemphigoid gestationis is an autoimmune blistering disorder (autoantibodies to basement membrane antigens such as BP180) causing complement-mediated dermo-epidermal injury and tense bullae.
Risk Factors
- Previous obstetric cholestasis or family history of cholestatic pregnancy disease
- Multiple pregnancy (increased risk of polymorphic eruption and cholestasis)
- Personal or family history of atopy/eczema (atopic eruption of pregnancy)
- Late second or third trimester gestation
- Possible association of polymorphic eruption with male fetus
- History of autoimmune blistering disease (relevant to pemphigoid gestationis)
Clinical Features
Symptoms
- Generalized or palmoplantar itch, often worse at night
- Itch preceding visible skin changes in some conditions
- Sleep disturbance, fatigue, and reduced quality of life
- Rash-associated itch: urticated papules/plaques (polymorphic eruption), eczematous or papular lesions (atopic eruption), severe itch with evolving blisters (pemphigoid gestationis)
- Dark urine, pale stools, or steatorrhoea may suggest cholestasis rather than primary dermatological disease
Signs
- Excoriations without primary rash suggest cholestasis (especially with normal-looking skin apart from scratch marks)
- Polymorphic eruption: erythematous urticarial papules/plaques, often beginning in abdominal striae with periumbilical sparing
- Atopic eruption: eczematous flexural patches or widespread prurigo-like papules
- Pemphigoid gestationis: periumbilical urticated plaques progressing to tense bullae
- Secondary skin infection signs (crusting, weeping) from scratching
Investigations
Management
Lifestyle Modifications
- Use soap substitutes/emollients frequently, keep nails short, wear loose cotton clothing, and avoid overheating
- Trigger reduction for eczema-prone skin (fragranced products, harsh detergents)
- Urgent obstetric review if itch is severe without rash, especially in third trimester, to exclude cholestasis
- Multidisciplinary care (obstetrics, dermatology, hepatology when needed) and fetal surveillance planning for cholestasis
- Image learning for exams: See Figure reference in your dermatology atlas for PUPPP striae-centered plaques and pemphigoid gestationis bullae patterns
Pharmacological Treatment
Antihistamines for symptomatic itch relief
- Chlorphenamine 4 mg orally every 4-6 hours when required (maximum 24 mg/day)
- Cetirizine 10 mg orally once daily
- Loratadine 10 mg orally once daily
Often reduce itch perception/sedation but do not treat cholestasis pathophysiology. Prefer non-sedating agents for daytime function; chlorphenamine may cause drowsiness and anticholinergic effects.
Topical anti-inflammatory therapy for rash-associated disease
- Hydrocortisone 1% cream or ointment thinly once to twice daily
- Clobetasone butyrate 0.05% thinly once to twice daily for limited moderate-severity areas
Use lowest effective potency and duration, especially on thin skin/flexures; avoid prolonged high-potency widespread use due to maternal skin atrophy and potential fetal growth concerns with very potent extensive exposure.
Systemic corticosteroid for severe inflammatory dermatoses (specialist-led)
- Prednisolone 20-40 mg orally once daily, then taper to minimum effective dose
Reserved for severe atopic eruption or pemphigoid gestationis. Monitor blood pressure, glucose, infection risk, and mood; balance maternal benefit against steroid adverse effects.
Therapy in obstetric cholestasis
- Ursodeoxycholic acid 10-15 mg/kg/day orally in 2-3 divided doses (specialist prescribing; some units titrate up to 20 mg/kg/day)
Used to improve maternal itch and biochemical profile; fetal benefit is less certain, so obstetric surveillance and delivery planning remain essential. Exclude other liver disease and monitor bile acids/LFTs serially.
Complications
- Obstetric cholestasis: increased risk of adverse perinatal outcomes including preterm birth and stillbirth risk at higher bile acid levels
- Pemphigoid gestationis: preterm delivery and low birth weight; transient neonatal rash from maternal autoantibodies
- Maternal sleep deprivation, anxiety, low mood, and impaired daily functioning
- Excoriation-related secondary bacterial skin infection
- Postpartum flare in pemphigoid gestationis around delivery
Prognosis
Most pregnancy-specific dermatoses improve after delivery, with symptomatic control achievable in most women. Recurrence in future pregnancies is common for cholestasis and pemphigoid gestationis, so clear documentation and early monitoring in subsequent pregnancies are important.
Sources & References
🏥BMJ Best Practice(1)
✅NICE Guidelines(1)
- Itch in pregnancy[overview]
📖Textbook References(1)
- Guyton and Hall Textbook of Medical Physiology (John E. Hall, Michael E. Hall) (Z-Library).pdf(pp. 587)[context]