Pregnancy-Related Rashes

Question 1

Briefly describe polymorphic eruption of pregnancy

Answer 1

Polymorphic eruption of pregnancy is also known as pruritic and urticarial papules and plaques of pregnancy. It is an itchy rash that tends to start in the third trimester. It usually begins on the abdomen, particularly associated with stretch marks (striae).

It is characterised by:

• Urticarial papules (raised itchy lumps)
• Wheals (raised itchy areas of skin)
• Plaques (larger inflamed areas of skin)

Question 2

How is polymorphic eruption of pregnancy treated?

Answer 2

The condition will get better towards the end of pregnancy and after delivery. Management is to control the symptoms, with:

• Topical emollients
• Topical steroids
• Oral antihistamines
• Oral steroids may be used in severe cases

Question 3

Briefly describe atopic eruption of pregnancy

Answer 3

Atopic eruption of pregnancy essentially refers to eczema that flares up during pregnancy. This includes both women that have never suffered with eczema and those with pre-existing eczema. Atopic eruption of pregnancy presents in the first and second trimester of pregnancy.

There are two types:

• E-type, or eczema-type: with eczematous, inflamed, red and itchy skin, typically affecting the insides of the elbows, back of knees, neck, face and chest.
• P-type, or prurigo-type: with intensely itchy papules (spots) typically affecting the abdomen, back and limbs.

Question 4

How is atopic eruption of pregnancy treated?

Answer 4

The condition will usually get better after delivery. Management is with:

• Topical emollients
• Topical steroids
• Phototherapy with ultraviolet light (UVB) may be used in severe cases
• Oral steroids may be used in severe cases

Question 5

Briefly describe melasma

Answer 5

Melasma is also known as mask of pregnancy. It is characterised by increased pigmentation to patches of the skin on the face. This is usually symmetrical and flat, affecting sun-exposed areas.

Melasma is thought to be partly related to the increased female sex hormones associated with pregnancy. It can also occur with the combined contraceptive pill and hormone replacement therapy. It is also associated with sun exposure, thyroid disease and family history.

Question 6

How is melasma treated?

Answer 6

No active treatment is required if the appearance is acceptable to the woman. Management is with:

• Avoiding sun exposure and using suncream
• Makeup (camouflage)
• Skin lightening cream (e.g. hydroquinone or retinoid creams), although not in pregnancy and only under specialist care
• Procedures such as chemical peels or laser treatment (not usually on the NHS)

Question 7

Briefly describe pyogenic granuloma

Answer 7

Pyogenic granuloma is also known as lobular capillary haemangioma. This is a benign, rapidly growing tumour of capillaries. It present as a discrete lump with a red or dark appearance. They occur more often in pregnancy, and can also be associated with hormonal contraceptives. They can also be triggered by minor trauma or infection.

Pyogenic granuloma present with a rapidly growing lump that develops over days up to 1-2 cm in size, (but can be larger). They often occur on fingers, or on the upper chest, back, neck or head. They may cause profuse bleeding and ulceration if injured.

Other differentials, such as malignancy, need to be excluded (particularly nodular melanoma).

Question 8

How is pyogenic granuloma treated?

Answer 8

When they occur in pregnancy, they usually resolve without treatment after delivery. Treatment is with surgical removal with histology to confirm the diagnosis.

Question 9

Briefly describe pemphigoid gestationis

Answer 9

Pemphigoid gestationis is a rare autoimmune skin condition that occurs in pregnancy. Autoantibodies are created that damage the connection between the epidermis and the dermis. The pregnant woman’s immune system may produce these antibodies in response to placental tissue. This causes the epidermis and dermis to separate, creating a space that can fill with fluid, resulting in large fluid-filled blisters (bullae).

Pemphigoid gestationis usually occurs in the second or third trimester. The typical presentation is initially with an itchy red papular or blistering rash around the umbilicus, that then spreads to other parts of the body. Over several weeks, large fluid-filled blisters form.

The rash usually resolves without treatment after delivery. It may go through stages of improvement and worsening during pregnancy and after birth. The blisters heal without scarring.

Question 10

How is pemphigoid gestationis treated?

Answer 10

Treatment is with:

• Topical emollients
• Topical steroids
• Oral steroids may be required in severe cases
• Immunosuppressants may be required where steroids are inadequate
• Antibiotics may be necessary if infection occurs

Question 11

What are the risks of pemphigoid gestationis to the baby?

Answer 11

The risks to the baby are:

• Fetal growth restriction
• Preterm delivery
• Blistering rash after delivery (as the maternal antibodies pass to the baby)