Rash in Pregnancy

Two patterns that are not ordinary

A rash that does not fade. Tommy's lists, among the signs of sepsis in pregnancy that mean calling 999, "a rash that does not fade when you press it or put a glass on it", alongside fast breathing, slurred speech, confusion, clammy, blotchy or mottled skin that can look bluish on some skin tones, not having a wee all day, and feeling very drowsy. Press a clear glass firmly against the rash. If the marks stay visible through the glass, call 999 and say you suspect sepsis.

Itching with no rash. The NHS puts this on its list of pregnancy symptoms you need to get help for: "Itching in pregnancy can be caused by your skin stretching, but it can sometimes be a sign of a liver condition called intrahepatic cholestasis of pregnancy (ICP) that may need treatment."

The pattern that points at ICP is itching without a rash, often worst on the palms of the hands and the soles of the feet, and often worse at night. It is diagnosed on a blood test, so the call is worth making rather than waiting to see if it settles.

A third combination worth naming: any rash arriving with a temperature, feeling unwell, or after contact with someone who has chickenpox, measles or slapped cheek, should be reported to your midwife or GP the same day rather than self-diagnosed.

The common, harmless rashes

Heat rash

The NHS describes prickly heat as small, raised spots, an itchy, prickly feeling, and mild swelling, appearing where you sweat. Pregnancy makes it more likely for a simple reason: the NHS says you are likely to feel warmer than usual and to sweat more, because of hormonal changes and more blood flowing to the skin. It typically appears in skin folds, under the breasts, at the waistband and under the bump.

The NHS advice is to keep cool, wear loose cotton clothing, use lukewarm water rather than hot, avoid perfumed shower gels and creams, and pat rather than rub the skin dry.

Hives

The NHS describes the main symptom of hives as an itchy rash that can be raised bumps or patches in many shapes and sizes, anywhere on the body, in one area or spread across it, and that can itch, sting or burn. On the colour it is careful: it looks pink or red on white skin, and "the colour of the rash can be harder to see on brown and black skin".

Hives usually settle within a few days. Antihistamines are the usual treatment, but not all are recommended in pregnancy, so ask your midwife or pharmacist rather than buying one off the shelf.

Skin changes that are not really rashes

ACOG groups the ordinary pregnancy skin changes together: dark spots on the breasts, nipples or inner thighs; melasma, meaning brown patches on the cheeks, nose and forehead; linea nigra; stretch marks; acne; spider veins; and varicose veins. It is honest about cause: "Some are due to changes in hormone levels that happen during pregnancy. But for most skin changes health care professionals are not sure of the exact cause."

Stretch marks are the one most often mistaken for a rash, particularly early. The NHS notes the first sign may be "itchiness around an area where the skin is becoming thinner", before any marks are visible.

The itchy bumpy rash of late pregnancy

An intensely itchy, raised rash appearing in the third trimester, often starting in stretch marks on the abdomen and spreading to the thighs and buttocks, while typically sparing the area immediately around the navel, is a recognised pregnancy-specific eruption. It is harmless to the baby and settles after birth, but it is genuinely miserable and worth having looked at rather than tolerated, partly because the important job is distinguishing it from cholestasis.

Tommy's is the most useful source on that distinction, and its instruction is simple: tell your midwife or doctor about itching in pregnancy so it can be assessed. A blood test is what separates the two, and it is quick.

What helps while you wait

• Cool the skin. Lukewarm showers, a fan, and loose natural fibres. Heat drives almost every itch in pregnancy.
• Unperfumed emollient. Plain moisturiser applied liberally and often. Keeping it in the fridge makes it more effective on an itch.
• Avoid perfumed products — shower gel, bubble bath, biological detergent.
• Cotton, and looser than feels necessary. Waistbands and bra bands are where heat rash starts.
• Keep nails short. Scratching turns an itch into broken skin and infection.
• Ask before buying anything. Antihistamines and steroid creams both come with pregnancy considerations. Your midwife or pharmacist can tell you which are appropriate.

When to ring rather than wait

• A rash that does not fade under a glass — 999.
• A rash with a temperature, or with feeling generally unwell — same day.
• Itching without a rash, especially palms and soles, especially at night — call your midwife or maternity unit.
• Any rash after contact with chickenpox, measles or slapped cheek, if you are not sure you are immune.
• A rash with swelling of the face, lips or tongue, or any difficulty breathing — 999.
• A rash that is spreading rapidly, blistering, or where the skin is peeling.

Everything else — itchy, hot, bumpy, unattractive and maddening — is usually one of the ordinary ones, and usually improves with cooling, emollient and time.