Information
Pregnancy results in a variety of physiological and pathological changes to the skin. The latter can be divided into two categories – those that can occur outside pregnancy and those that are unique to pregnancy. Idiopathic pruritus without obvious skin eruption is a common problem.
The four dermatoses of pregnancy are:
- atopic eruption of pregnancy
- pemphigoid gestations
- polymorphic eruption of pregnancy
- intrahepatic cholestasis of pregnancy (often referred to as obstetric cholestasis)
Diagnosis and management are dependent upon a structured history and examination and understanding of serious and/or common dermatoses that may require referral to a dermatologist.
Who to refer :
In general women should be referred to an obstetric consultant if they have symptoms and signs of the following dermatoses in pregnancy:
- Pemphigoid gestationis.
- Intrahepatic cholestasis of pregnancy.
Consider referring to dermatology
- Pemphigoid gestationis.
- Polymorphic eruption of pregnancy, atopic eruption of pregnancy or a localised area of itching or skin eruption where initial management fails.
- Skin eruptions associated with systemic symptoms.
Ideally, patients with any skin eruption should be seen in a joint obstetric/dermatology clinic. We do not have a joint clinic set up in NHS Lothian in the current time. Referrals can be made to the Obstetric Medicine Specialty clinic [obstetricmedicine@nhslothian.scot.nhs.uk] or Locality Obstetric Consultant clinic.
No rash
Obstetric cholestasis
Obstetric cholestasis should first be considered as a diagnosis of exclusion in any pregnant woman presenting with itching in the absence of a rash. It affects approximately 1% of pregnancies in the UK, but may affect a higher proportion of women from Indian or Pakistani-Asian ethnic origin. Itching is usually focussed in the palms of the hand and soles of the feet, but may also affect the scalp, anus, vulva and abdomen. Obstetric cholestasis can increase the risk of stillbirth and postpartum haemorrhage.
LFTs and total bile acids (TBAs) should be taken between 30 and 120 minutes after eating. Liver function test results should be checked the next day. Normal values for pregnancy:
- ALT 10-40 U/L (falling to 30 U/L in third trimester)
- ALP <500
- GGT 5-35 U/L (raised by 20% in obstetric cholestasis)
- Bilirubin 2-16 umol/L (not commonly raised in obstetric cholestasis
- Total bile acids <19
TBAs results can take a few days to come back from the lab. Raised ALT or GGT and/orpost-prandialbile acids >19 would be suggestive of obstetric cholestasis.
Women with obstetric cholestasis should be referred to the Day Assessment Unit at the Royal Infirmary of Edinburgh (0131 242 2656), or Day Beds at St John’s Hospital Livingston for monitoring.
Treatment will be arranged through the hospital and will involve:
- Bile acids <40: Manage itch, monitor weekly LFTs and bile acids, weekly CTG monitoring,? commence UDCA if itch ongoing, offer induction of labour at EDD.
- Bile acids ≥40: Commence UDCA, manage itch, monitor weekly LFTs and bile acids, twice weekly CTG monitoring, offer induction of labour at 38 weeks.
Idiopathic pruritis
Idiopathic pruritus without obvious skin eruption is a common problem. Therapies to help control the itch include:
- Calamine lotion
- Aqueous cream with 1%menthol
- Chlorphenamine (Pirton) 4mg 4-6hourly (max 24mg daily) or Cetirizine 10mg daily
Rash
Initiate treatment to offer relief from symptoms and refer women to a dermatologist.
| Dermatoses of pregnancy | Areas affected | Risk factors | Recurrence risk | Management | Pregnancy outcome |
| Atopic eruption of pregnancy | Face, neck, chest and extensor surfaces of the limbs and trunk | Family history of atopy | Limited data | Oatmeal baths, Topical emollients Topical anti-pruritics Topical steroids Antihistamines Ultraviolet light Topical acne treatment | No adverse effect on mother or fetus |
| Polymorphic eruption of pregnancy | Abdominal striae with periumbilical sparing Can progress to trunk and extremities, sparing palms, soles and face | Nulliparity, multiple pregnancies Any cause of overdistension of skin | Rarely recurs | Topical steroids (first-line) Topical emollients Antihistamines Oral steroids | No adverse effect on mother or fetus |
| Pemphigoid gestationis | Appears around umbilicus unlike PEP Can progress to trunk, extremities, palms and soles with mucosal sparing | Recognised correlation with the haplotypes HLA-DR3 and HLA-DR4 Other autoimmune conditions | May recur in subsequent pregnancies, with earlier onset and increasing severity Also, may recur with oral contraception/ menstruation | Topical/oral corticosteroids Antihistamines Antibiotics Immunophoresis Immunosuppressants | IUGR ? Preterm labour Self-limiting skin lesions in neonate |
- Skin eruptions specific to pregnancy: an overview. Maharajan A, Aye, C, Ratnavel R, Burova E. TOG volume 15. Issue 4 October 2013 Pages 233-240.
https://doi.org/10.1111/tog.12051
- Royal College of Obstetricians and Gynaecologists. Obstetric Cholestasis. Green-Top Guideline No. 43. London: RCOG; 2011
Obstetric Cholestasis (Green-top Guideline No. 43) (rcog.org.uk)
