Heat rash looks like tiny bumps, bug bites, or pimples. You may have seen it on babies, but it's also very common during pregnancy. Wearing light, loose clothing and keeping cool with air conditioning, cool or tepid baths, and cool, wet washcloths can soothe the itch of this annoying skin condition.

Learn more about why heat rash happens during pregnancy and what you can do about it.

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Key Takeaways
  • Heat rash is common during pregnancy and is caused by trapped sweat. Pregnancy can increase body temperature and make you sweat more, which can clog sweat ducts and lead to small red or pink bumps that may itch or sting.
  • Keeping cool and reducing friction are the best ways to treat and prevent heat rash. Loose cotton clothing, cool compresses, tepid baths, fans, and air conditioning can reduce itching and help the rash heal. Calamine lotion and talc-free powders may also provide relief.
  • Most heat rashes are harmless, but persistent or severe symptoms should be checked by a doctor. See your doctor if the rash lasts more than a few days, becomes painful, shows signs of infection, or is accompanied by other concerning symptoms.

What are the symptoms of heat rash during pregnancy?

heat rash
Science Source; iStock

Heat rash appears as pink or red, bug-bite-like bumps that can itch or feel prickly or sensitive. It can sometimes look like pimples and may even develop whiteheads.[1]

You're most likely to see it in areas where sweat becomes trapped between the folds of your skin, such as:

  • In the creases between and beneath the breasts
  • Where the bulge of the lower abdomen rubs against the top of the pubic area
  • On your back
  • On the inner thighs
  • On the armpits
  • In the creases of your elbows

"I get heat rashes a LOT when pregnant!" says What to Expect Community member eclaire24. "Often on my thighs or under my boobs."

It can easily be confused with with other pregnancy-related skin conditions, such as:

  • Hives, or itchy, raised welt-like bumps that can appear suddenly on the body, usually as an allergic reaction. Hives tend to last anywhere from a few days to a few weeks.
  • Prurigo, which often appears as itchy, crusty bumps on your arms or legs, and can happen at any point in pregnancy.
  • Pruritic folliculitis, which causes acne-like, pus-filled bumps that may appear on your torso and spread to your arms, chest, and back. It typically develops during the second trimester or third trimester.
  • Pemphigoid gestationis, which is a rare autoimmune skin disorder that can suddenly pop up in the second or third trimester and cause a hive-like rash on your midsection that can turn into blisters.
  • Cholestasis of pregnancy, which is an intense itch all over your body, particularly on the palms of the hands and soles of the feet. It typically shows up in the third trimester and may be accompanied by nausea, vomiting, and jaundice (the whites of the eyes and skin may be yellow-colored). Cholestasis is not actually a rash — it's a sign of liver disease triggered by your hormones and should be evaluated by a doctor.
  • Pustular psoriasis of pregnancy, which is a severe form of pustular psoriasis that appears as red, inflamed, crusty lesions — commonly on the thighs and groin — during the second half of pregnancy.
  • Pruritic urticarial papules and plaques of pregnancy (PUPPP), which appears as itchy, red, raised skin patches on the stomach, often near stretch marks, and can spread to your limbs. PUPPP typically only develops in your first pregnancy, during the third trimester.

What causes heat rash during pregnancy?

Also known as prickly heat, heat rash happens when the sweat ducts in your pores become clogged, trapping perspiration beneath the skin. It tends to crop up during the hot, humid months.

Heat rash can be triggered by a combination of pregnancy-related changes: increased body heat, excessive perspiration, and friction from skin rubbing against itself or clothing. While it's not pretty, fortunately prickly heat is usually only slightly irritating.

"I am very prone to heat rash normally, so I expected it in pregnancy," says Community mom BoyMomEst2023. "But it came on so much faster than usual!"

Track your symptoms with the MyJournal tool in our free What to Expect app.

How do I treat heat rash during pregnancy?

Wondering how to beat the heat? There are plenty of pregnancy-safe ways to soothe itchy skin and help heal your heat rash.

  • Wear light, loose-fitting cotton clothes. To help minimize sweating and friction, avoid tight-fitting clothing and leggings. And choose your fabrics wisely — synthetic material can worsen sweating, and scratchy ones like wool can cause itching.
  • Apply a cool, damp compress to your skin. To cool the rash, try soaking a washcloth in cold water or chilled green tea and applying it to the affected area for five minutes, three times a day.
  • Rinse off. Take warm or tepid (not hot) baths and showers — and don't linger for too long, use harsh soaps, or make the water too hot. A tepid oatmeal bath can also be very soothing, as oatmeal contains compounds that relieve inflammation.
  • Pat on powder. Sprinkle a bit of cornstarch or talc-free powder to absorb sweat during the day.
  • Apply calamine lotion. It contains zinc oxide, which has soothing properties and can temporarily relieve itching as it dries.
  • Turn on the air conditioning or a fan. This can help you avoid overheating, stay cool, and keep sweat at bay.
  • Get naked. And stay that way whenever you can. Fresh air is the best antidote to heat rash.
  • Ask your doctor about hydrocortisone cream. Many over-the-counter heat rash remedies contain hydrocortisone, a common anti-itch ingredient. But before you apply the medication, check with your dermatologist or pharmacist to make sure the ingredients are safe to use during pregnancy.

"It was behind my knees and in my elbow crease," says Community mom OnlyaGeniousCouldLoveMe. "I used hydrocortisone cream. Went away in about a week and a half. No issues ever since!"

What remedies don't work for pregnancy heat rash?

You should steer clear of some treatments and products when you have heat rash during pregnancy, including:

  • Skin irritants. Stay away from perfumes, fragranced lotions, and harsh soaps.
  • Petroleum-based ointments or mineral oil creams. Heavy creams or oils can worsen heat rash because they may further block sweat ducts.

When should I see a doctor about heat rash during pregnancy?

Usually, heat rashes are harmless. But there are certain symptoms that may warrant a call to your doctor, including:

  • If the rash or irritation lasts longer than a couple of days.
  • If you're experiencing pain or intense itching.
  • If the rash becomes infected — for example, it leaks pus or fluid, or is accompanied by symptoms like swelling, fever, and nausea.

While it may not be pretty or comfortable, in all likelihood, your heat rash will fade within a few days — and be nothing more than a mild inconvenience.


Heat Rash During Pregnancy FAQs

You can treat heat rash during pregnancy by taking a warm, tepid, or cool bath, staying in a cool, air-conditioned room, and applying a cool damp washcloth soaked in cool water or green tea to the area three times a day for about five minutes at a time.

Heat rash appears as clusters of tiny red, pink, or clear bumps on the skin that are often itchy or feel prickly. Heat rash can look like small bug bites or pimples.

Heat rash usually disappears on its own, whether you're pregnant or not, and typically won't last more than a few days. If you've had heat rash for longer than three days, call your practitioner.

No, heat rash isn't contagious and doesn't typically spread, though you can exacerbate the rash by scratching it too much or using lotions, oils, or powders.