Skin problems in pregnancy

Introduction

Hormonal changes in pregnancy may result in physiological alterations in the skin, hair and nails. Examples include:

• Appearance or darkening of a vertical band down the middle of abdominal skin (linea nigra), which may normally appear paler than normal skin (linea alba)
• Darkening of areola, nipple, and genital skin
• Increased redness of palms (palmar erythema) and vasomotor instability (flushing)
• Telangiectasia (dilated small re blood vessels), venulectasia (dilated blue-coloured vessels) and varicose veins
• Telogen effluvium (hair shedding) after the baby has been born
• Striae gravidarum (stretch marks)
• Skin tags on the neck, in the armpit and groin
• Hyperhidrosis (increase in sweating)

Palmar erythema

Linea nigra

Telogen effluvium

Striae gravidarum

Pregnancy may result in the onset of or worsening of some common and uncommon skin problems. These include:

• Facial pigmentation (melasma)
• Atopic dermatitis  
• Vesicular hand dermatitis 
• Psoriasis  
• Acne (in early pregnancy)
• Perioral dermatitis
• Pyogenic granuloma
• Generalised pustular psoriasis
• Systemic lupus erythematosus

Some skin conditions are reported to improve in pregnancy (at least sometimes).

• Atopic dermatitis  
• Psoriasis (may worsen, improve, or stay the same)
• Acne (in late pregnancy)
• Hidradenitis suppurativa
• Fox-Fordyce disease

When prescribing for skin diseases, safety of medicines in pregnancy must be carefully considered.

Melasma

Perioral dermatitis

Pyogenic granuloma

Generalised pustular psoriasis

Itchy rashes during pregnancy

Itch (pruritus) is relatively common in pregnancy. Causes include scabies, atopic eczema, contact irritant dermatitis etc. Some specific itchy conditions that arise in pregnancy follow.

Cholestatic pruritus

Intrahepatic cholestasis affects about 1% of pregnancies. It results in unexplained pruritus (itch) during the second and third tremesters, with raised blood levels of bile acids and/or liver enzymes. Intrahepatic cholestasis is associated with:

• Increased risk of preterm delivery
• Stillbirth (rare)
• Increased risk of later hepatobiliary cancer (2–3 times greater than the risk in women in whom pregnancy occurred without intrahepatic cholestasis)
• Increased risk of later thyroid disease, diabetes, psoriasis, Crohn disease and cardiovascular disease

Prurigo of pregnancy

Prurigo of pregnancy (papular dermatitis of pregnancy) presents as scattered itchy/scratched papules at any stage of pregnancy. It should be managed with emollients, and topical steroids may help individual papules.

Prurigo of pregnancy

Prurigo of pregnancy

Prurigo of pregnancy

Polymorphic eruption of pregnancy

Polymorphic eruption of pregnancy is also called PUPPP, an acronym for Pruritic Urticarial Papules and Plaques of Pregnancy. Features include:

• Onset of PUPPP is in the 3rd trimester and remission occurs within a few days of delivery
• It more frequently arises in primigravidae and multiple pregnancies
• Itchy erythematous papules and plaques first appear on abdominal striae and then spread to trunk and proximal limbs; umbilicus is spared
• Direct immunofluorescence is negative (unlike pemphigoid gestationis)

Emollients, medium potency topical steroids and sedative oral antihistamines provide relief of symptoms. In severe cases, systemic steroids may be necessary.

Pemphigoid gestationis

Pemphigoid gestationis is a rare blistering disease due to circulating IgG autoantibodies similar to those found in bullous pemphigoid, targeting a basement membrane zone protein BPAG2 (BP180) within the hemidesmosome. Features include:

• The onset of pemphigoid gestationis is most often in the 2nd trimester (weeks 13 to 26), but it may arise at any stage and may even be worse postpartum
• It can recur with menstruation, with oral contraceptives and in further pregnancies
• The itchy papules mainly affect the abdomen, including umbilicus, but may generalise, with grouped or annular red papules, plaques and blisters
• Direct immunofluorescence (a test done as part of a skin biopsy) shows deposition of C3 and or IgG or other antibodies
• Severe pemphigoid gestationis should be treated by oral corticosteroids.

Pemphigoid gestationis

Pemphigoid gestationis