Polymorphic eruption of pregnancy (PEP)

Polymorphic eruption of pregnancy (PEP) is an itchy rash that can develop when you're pregnant. It is also known as 'pruritic urticarial papules and plaques of pregnancy (PUPPP)'.

It affects around 1 in 160 pregnancies. It usually appears in the third trimester, often between week 36 and 39 of pregnancy. Occasionally it can start after birth. It usually goes away within a few weeks after your baby is born.

PEP is a red, bumpy rash that typically starts in or near stretch marks on your abdomen (tummy).

It starts with small spots, called papules, which join to form larger red areas called plaques. It can spread to your buttocks, legs and arms.

The rash is itchy and can disturb your sleep.

The cause of PEP is not known, but it may be connected to skin stretching during pregnancy. It is thought that sudden stretching causes damage to the connective tissue in your skin, leading to inflammation.

PEP is more likely to develop if:

• this is your first pregnancy
• you are pregnant with twins — and even more likely if you are pregnant with triplets or other multiples
• your baby is big
• you gain a lot of weight during pregnancy

People with darker skin are less likely to have PEP.

See your doctor or midwife if you have an itchy rash when you're pregnant. It's important to rule out other causes of itch during pregnancy, as some can be harmful for your baby.

There are no medical tests for PEP. Your doctor or midwife will examine you and ask about your symptoms. They can usually tell if you have PEP from your symptoms and how your rash looks. If they are not sure, they may refer you to a specialist, such as a dermatologist (skin specialist).

Sometimes it can be hard to tell what's causing your rash. If so, your doctor or midwife might arrange for you to have a skin biopsy or a blood test to check for other conditions.

There's no treatment for PEP, but there are things you can do to help reduce the symptoms, and make you more comfortable.

Use moisturiser as much and as often as you need. A good time to apply moisturiser is right after a shower. Before using any creams, check with your pharmacist if they are safe in pregnancy.

Here are some other things you can try to help relieve itch:

• Have a cool shower.
• Avoid having long showers.
• Wear loose clothing and avoid getting too hot.
• Use a plain soap that doesn't have added fragrances.
• Avoid things that can worsen itch, such as rough fabrics, caffeine and alcohol.
• Try soaking in a cool oatmeal bath.
• Ask your pharmacist for a soothing cream or lotion containing menthol.

Medicines to relieve itch

If you're still itchy, talk to your doctor or pharmacist about medicines that may help. Your doctor may prescribe you a steroid cream, such as betamethasone. Apply a thin layer of cream to the itchy areas only.

You can try an antihistamine, such as cetirizine. Ask your pharmacist which antihistamines are safe to use in pregnancy.

If your itch is severe, you may need a short course of steroid tablets, such as prednisolone. Talk to your healthcare team about what is right for you.

PEP is not harmful to you or your baby. There's a very small chance that your baby could be born with a mild PEP rash, but it will fade quickly.

If you notice a rash on your baby, ask your midwife or paediatrician for advice.

Read more on common childhood rashes.

There is nothing you can do to prevent PEP. If you have PEP, it is not likely to happen again in a future pregnancy.

Visit the Australian College of Dermatology to read more on polymorphic eruption of pregnancy, including causes and diagnosis.

The Royal Women's Hospital has helpful information on common concerns in early pregnancy, including skin changes and itching.

If you are pregnant or breastfeeding and would like to find out more about your medicines, call Medicines Line on 1300 633 424.

Looking for information for Aboriginal and/or Torres Strait Islander people?

You can find out more about Aboriginal and/or Torres Strait Islander pregnancy health on Stronger Bubba Born or watch the How to Have a Safer Pregnancy video.

Do you prefer to read in languages other than English?

The Multicultural Centre for Women's Health has a catalogue of health resources for women, available in more than 70 languages.