The skin in pregnancy

Introduction

The skin undergoes profound alterations during pregnancy as a result of endocrine, metabolic, and physiological changes. Some of these are trivial and chiefly cosmetic, producing no or minor symptoms, others can be distressing and/or of major medical importance. Pregnancy will profoundly modify expression of pre-existing skin disease and there are dermatoses which are specific to pregnancy: these are described in detail below.

Common Skin Changes in pregnancy

Vascular changes and lesions
There is increased skin blood flow during pregnancy and this makes the skin more prone to itch and to oedema, manifest as tightening of rings and shoes. Spider naevi and palmar erythema are common, as are haemangiomas. Pyogenic granuloma may develop: this is a benign tumour with a tendency ulcerate and to bleed, and is sometimes clinically confused with melanoma. It often recurs after local destruction.

Pigmentary changes and pigmented lesions
There is darkening of the nipples, genitalia, and linea alba. The unsightly and sometimes psychologically distressing facial pigmentation of melasma (chloasma) affects many women, is worse with sunlight, and can be reduced by the use of high protection factor (SPF 25) UVB and UVA sun screens.

Pigmented naevi can increase in number, size, and pigmentation. Melanoma may occur and is associated with a poor prognosis in pregnant women. Any rapidly changing, irregularly shaped, or irregularly pigmented mole should be biopsied to exclude a dysplastic naevus or melanoma.

Hair changes
There is diminished shedding of hair, due to prolongation of anagen. This is perceived as thickening of the hair, which increased sebum secretion makes appear more lustrous. The synchronized shedding after parturition gives rise to the distressing postpartum telogen effluvium. Hirsutism may begin or worsen in pregnancy as there is an associated increase in androgens.

Pilosebaceous changes
The increased oestrogens of pregnancy usually improve acne, but there may be worsening of acne in some unfortunate patients, and the entire skin is usually greasier.

Striae
Striae on the breasts and abdomen are very common in pregnancy, but do not necessarily relate to either the total weight gain or the rate of weight gain. There is much individual variation.

Cutaneous infections
Candida of the vulva as well as the vagina may occur. Cutaneous and genital warts thrive in pregnancy. Treatment of genital warts is by physical destruction as podophyllin must not be used in pregnancy. Genital herpes simplex infections can pose problems as regards delivery during active infections.