Key content
Pregnancy results in various physiological skin changes.
As a consequence, some common dermatoses can present more
frequently in pregnant women. In addition, there are a number
of skin eruptions unique to pregnancy.
The aetiology of physiological skin changes in pregnancy is
uncertain but is thought to be due to hormonal and physical
changes of pregnancy.
The four dermatoses of pregnancy are: atopic eruption
of pregnancy, pemphigoid gestationis, polymorphic
eruption of pregnancy and intrahepatic cholestasis
of pregnancy.
Learning objectives
To understand the physiological skin changes in pregnancy.
To identify the skin conditions that require appropriate referral.
To be able to take a history, to diagnose the skin eruptions unique to
pregnancy, undertake appropriate investigations and first-line
management, and understand the criteria for referral to a
dermatologist.
Keywords: atopic eruption of pregnancy / intrahepatic cholestasis
of pregnancy / pemphigoid gestastionis / polymorphic eruption of
pregnancy / skin eruptions
Introduction
Pregnancy is a physiological state that is associated with specific
dermatoses and modification of common dermatoses. Various
hormonal, immunological and haemodynamic factors that are
specific to pregnancy influence the status of the skin. There
have been a number of attempts to create a universal
classification, however, more recently, a clinically approved
classification by Ambros-Rudolph and M€ullegger has been
widely accepted.1 The classification recognises atopic eruption
of pregnancy, pemphigoid gestationis, polymorphic eruption
of pregnancy and intrahepatic cholestasis of pregnancy to be
unique to pregnancy. This review provides an explanation of
the possible aetiology of the physiological skin changes and
skin eruptions specific to pregnancy, their diagnosis,
management and implications.
Physiological skin changes in pregnancy
Most physiological skin changes are recognised to be due
to hormonal (increased estrogen, progesterone and
melanocyte-stimulating hormone) and physical factors but
the exact aetiology is uncertain. Box 1 summarises
these changes.2,3
Almost all women notice an increase in skin pigmentation
during pregnancy, which is more noticeable in dark-skinned
individuals. This usually fades post-delivery, but often does
not disappear completely. Melasma has been reported in 75%
of expectant mothers, predominantly in the second or third
trimester. The condition is distressing and often persists for
months and years postpartum. Treatment can prove
challenging, with limited response to topical bleaching
creams, hydroquinones (not licensed in the UK), retinoids
and steroids, as well as chemical peels, laser treatments and
dermabrasion.4 All of the above treatments are
contraindicated in pregnancy and breastfeeding. Avoidance
of excessive sunlight exposure and the use of broad-spectrum
sunscreens are therefore essential to prevent both initial
development and exacerbation of melasma.5
Stretch marks (striae gravidarum) are also a common
concern. These develop as linear red–purplish areas resulting
from the stretching of skin in the second trimester. Striae
gravidarum (Figure 1) occur predominantly on the
abdomen, breasts, thighs, lower back, buttocks and upper arms. They are caused by the rupture of dermal elastic fibres,
which explains their irreversible nature. However, they often
fade in the postnatal period to thin, atrophic, hypopigmented
scars. Risk factors include personal or family history,
dark-skinned women and excessive abdominal distension in
pregnancy. Use of emollients is helpful, but there is no
evidence that preparations such as vitamin E cream, tea tree
oil and so on have any special valuePhysiological skin changes in pregnancy
Pigmentation
Linea nigra (abdomen)
Nipples
Axillae
Genitalia
Perineum
Secondary areola (pigmented area appears around the primary
areola commonly during the fifth month)
Melasma (chloasma gravidarum or pregnancy mask):
- Forehead
- Malar distribution
- Mandibular area
Glands
Eccrine
- Miliaria
- Hyperhidrosis
Apocrine
- Decreased activity (improves conditions such as hidradenitis
suppurativa)
Sebaceous
- Activity increased in third trimester but effects on acne variable
- Montgomery tubercles (follicles) may develop (hypertrophic
sebaceous glands, non-pigmented elevations in the primary areola)
Vasculature
Spider naevi
Telangiectasia
Palmar erythema
Varicosities:
- Saphenous
- Vulval/vestibular/vaginal
- Haemorrhoidal
Vasomotor instability, such as, flushing
Increased hydrostatic pressure, such as, purpura
Increased capillary permeability, such as, oedema in extremities and face
Connective tissue
Striae gravidarum
Skin tags (epithelial polyps)
History taking: specific questions to ask
Duration of the disease
Distribution and progression of the condition
Exacerbating or relieving factors
Associated symptoms like itching, burning, pain, weeping and redness
Family history of skin disorders
Social history, such as, job, travel
Past medical history, such as, asthma, hay fever
Drug history and allergies
Past dermatological problems
Previous treatments tried for this condition
Impact of condition on quality of life
Examination
Distribution
Site
Symmetry:
- Symmetry suggests endogenous cause
- Non-symmetry suggests an exogenous cause e.g. infection, irritant
or contact dermatitis
Description of primary lesion
Shape
Size
Colour
Margin
Surface
Type of lesion – papule, pustule, wheal, vesicle, bulla
Conclusion
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.
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,