Dermatology in pregnancy — Viva

Q1: How do you approach itch in pregnancy?

Expected answer: Start with gestational age, whether there is a primary rash, distribution, morphology and danger signs. Itch without a primary rash is intrahepatic cholestasis of pregnancy until serum bile acids and LFTs are checked. A primary rash is sorted by pattern: early eczema or papules suggests atopic eruption of pregnancy; late urticarial papules in striae with umbilical sparing suggests PEP/PUPPP; periumbilical plaques or bullae suggests pemphigoid gestationis; fever and pustules suggests pustular psoriasis of pregnancy.

Q2: Distinguish PEP/PUPPP from pemphigoid gestationis.

Expected answer: PEP/PUPPP is usually late third trimester, commoner in primigravidae or multiple gestation, starts in abdominal striae and usually spares the umbilicus. It has no primary tense bullae, negative DIF if tested, no fetal risk and resolves postpartum. Pemphigoid gestationis occurs in second/third trimester or postpartum, often starts periumbilically, progresses to tense bullae, has anti-BP180 autoimmunity and DIF linear C3 at the basement membrane zone. It is associated with prematurity, small-for-gestational-age infants and rare transient neonatal blistering, and it recurs in later pregnancies.

Q3: What do you investigate in suspected ICP?

Expected answer: Order serum bile acids and LFTs including ALT, AST and bilirubin. Repeat bile acids/LFTs if itch persists and the first result is normal because symptoms may precede biochemical elevation. If presentation is atypical or LFTs are marked, evaluate viral hepatitis, gallstones/biliary obstruction, drug liver injury and pregnancy liver disease such as pre-eclampsia/HELLP. Peak bile acids stratify fetal risk; 100 micromol/L or more carries the clearest stillbirth signal.

Q4: What is your management of ICP?

Expected answer: Involve obstetrics. Treat maternal itch with ursodeoxycholic acid 10 to 15 mg/kg/day orally in two or three divided doses, plus emollients, cool environment and sleep-directed antihistamine if needed. Explain that UDCA may improve itch but does not replace bile-acid-guided obstetric planning. Monitor bile acids/LFTs per local protocol, discuss delivery timing by peak bile acids, gestation and comorbidity, and recheck bile acids/LFTs postpartum, commonly at 4 to 6 weeks.

Q5: A pregnant patient has fever, malaise and flexural pustules. What is your concern?

Expected answer: Pustular psoriasis of pregnancy, historically called impetigo herpetiformis. It is not bacterial impetigo and not herpes. Admit; assess maternal observations and fetal wellbeing; check FBC, CRP, electrolytes, calcium, magnesium, albumin, renal/liver tests and cultures; biopsy if uncertain. Correct dehydration and hypocalcaemia, exclude infection, and treat with systemic therapy such as prednisolone, ciclosporin or selected biologic therapy under dermatology-obstetric specialist care.

Q6: Name safe and unsafe dermatology drugs in pregnancy and lactation.

Expected answer: Usually compatible in pregnancy: emollients, low/moderate topical corticosteroids, azelaic acid, benzoyl peroxide, selected topical antifungals/antibiotics, narrowband UVB, loratadine or cetirizine. Use with specialist caution: potent topical steroids, topical tacrolimus, oral prednisolone, ciclosporin and biologics. Avoid in pregnancy: systemic retinoids, acitretin, topical retinoids as precaution, methotrexate, mycophenolate, finasteride, griseofulvin and tetracyclines especially after early pregnancy or with prolonged use. Breastfeeding is checked separately by exact agent, dose, route, infant age and LactMed/local guidance; avoid or specialist-check methotrexate, mycophenolate, cyclophosphamide and oral retinoids.^[4]

Q7: What counselling do you give after PG or ICP?

Expected answer: PG may flare postpartum and commonly recurs in later pregnancies, often earlier and sometimes more severely; counsel about neonatal transient blistering and fetal growth/prematurity risk. ICP usually improves after delivery but needs postpartum LFT/bile-acid normalisation, recurrence counselling and advice that estrogen-containing contraception may provoke cholestasis in susceptible women, so contraception should be individualised.^[9][7]