Heat Rash On Babies: Causes & How To Treat It

“What is that rash?” Is a game commonly played by parents of infants. The internet is riddled with pictures of bare-chested babies displaying disconcerting patches of red.

You’re here because your little one’s skin is red and angry-looking. You wonder if it’s serious or if you can take the “wait-and-see” approach to avoid a trip out and a doctor’s bill.

This article will tell you all you need to know about the most common rash in babies: heat rash.

In addition, we’ll explore other rash symptoms and appearances so you can rule out anything Dr. Google might have frightened you with – and, finally, we’ll talk about the natural and home remedies you can use to try to prevent heat rash, bring your little angel relief, and keep this condition from coming back.

Let’s get started!

What Exactly Is Heat Rash?

You’re undressing your baby for a bath or a diaper change, and in the creases of his neck, armpits, thighs, and/or those adorable fat rolls is a furious swath of red bumps or a patch of red.

The most likely cause is heat rash, a rash that breaks out when the pores of the skin get blocked and sweat can’t escape.

We all sweat from glands in our skin to release heat from our bodies, but when that ability is prevented by tight clothing, fat folds or creases, our skin becomes inflamed, pink or red, even covered with small white or red bumps.

This happens in hot weather, often during the summertime, giving it the name of “summer rash”, but heat rash can occur any time of the year and in just about any weather condition.

Heat rash also happens with other illnesses, such as when fever chills cause someone to bundle up in blankets and warm clothes. Heat rash does not cause fevers.

Heat rash can also be caused when thick, perfumed lotions or creams are regularly used on the skin, blocking the pores and preventing sweat from releasing.

Heat rash affects children (and adults) of all ages, though it is most common in babies under 1 year of age.

It’s also called “prickly heat” (due to how it feels) and “miliaria” (not to be confused with malaria, which is an entirely different and very serious illness unrelated to heat rash).

Babies often get heat rashes because their pores are underdeveloped, making it hard for them to regulate their own body temperature and sweat when they get too hot.

Your little tyke is probably uncomfortable with a heat rash – though don’t worry, he probably isn’t in pain because of it.

Heat rashes tend to be itchy or “prickly” feeling, and young babies can’t rub away the itch on their own. This can become a chronic problem if your baby is particularly roly-poly.

Note from Dr. Leah Alexander, M.D., F.A.A.P.: “Here’s a great, patient-friendly overview article from the Cleveland Clinic: https://health.clevelandclinic.org/child-heat-rash-cool-heres/

Mild, Moderate & Extreme

There are three types of heat rashes.

The most common is called Miliaria Crystallina.

This happens frequently in babies and is characterized by small white fluid-filled bumps on the skin.

These bumps are essentially clogged pores filled with sweat that burst painlessly on their own. It doesn’t itch and shouldn’t be painful.

Moderate heat rash is called Miliaria Rubra.

This type of heat rash affects a deeper layer of skin and is more irritating, creating the famous “prickly heat” sensation we mentioned earlier.

When this kind of rash progresses and the bumps fill with puss, this becomes an extreme form of heat rash called Miliaria Profunda.

It’s not very common, but it can be difficult to get rid of.

Miliaria Profunda is a long-term or chronic version of a heat rash that occurs in the dermis layer of the skin.

It is much more common in adults than babies and can lead to nausea and dizziness due to the body’s inability to release sweat as effectively.

More than likely, your baby’s heat rash belongs in one of the first two categories, but other symptoms can make diagnosing it confusing.

If you have additional concerns about your baby, don’t hesitate to talk with your baby’s pediatrician.

Note from Dr. Leah Alexander, M.D., F.A.A.P.: “If you would like to learn more about the three types of heat rash mentioned here, the following is a link to an article from Stanford University that provides pictures and graphics of what is described in this section: https://stanfordmedicine25.stanford.edu/blog/archive/2017/Miliaria.html

What’s That Smell?

You might have heard somewhere that babies don’t stink and that they don’t need frequent baths like older kids and adults do.

But then you lean in to kiss that sweet round baby face and catch the smell of something funky.

When you peel back the layers, you might see a milky white or yellowish goop stuck in the deeper crevices of your baby’s skin.

What is that?

In mom circles this is referred to as “neck cheese”, and it can stink something awful.

This often accompanies a heat rash, and the redness plus the white substance may lead you to think the rash is infected, but don’t worry; this “cheese” is a normal buildup that occurs in babies when the skin rubs together, and this friction is also what is causing the heat rash.

If the skin looks raw, shiny, or is broken and weeping, there may be cause for concern about infection.

Action should be taken immediately to clean the area, dry the skin, and keep baby cool.

If the rash is extremely persistent and normal creams and the clean/dry techniques don’t work to give your baby relief, your baby might have a yeast infection with the rash.

Yeast breed under warm, moist conditions, so your baby’s fat rolls are the perfect ground for this kind of infection.

Many of the home remedies for heat rash can help cure a simple yeast infection, too, so keep reading for ways to address both issues.

When To Call The Doctor

Heat rashes are usually a harmless indicator that your baby is a little too hot.

Treating it is simple, but something more serious might be going on if your baby has the following symptoms:

  • Develops a fever
  • Shaking or trembling, as if from chills
  • Lethargic or excessively sleepy
  • Refusing to nurse or take a bottle
  • Increased pain
  • Suspected yeast infection
  • Pus draining from the rash bumps on their skin
  • Rash lasts longer than a few days without any change or gets worse

Other Rashes Not To Be Confused With Heat Rashes

The following rashes can be commonly confused with heat rash; so knowing the differences can help you avoid a trip to the doctor or help you make the smart choice to set an appointment.

1) Eczema

This skin condition is pretty common for babies these days; it affects thousands of babies every year, due to the sensitivity of their skin.

Eczema is characterized by dry, sometimes flaky, raised patches of skin that can be found anywhere on the body – ones that are often itchy.

Heat rash, on the other hand, is bright red and can be bumpy, and doesn’t usually appear dry.

Note from Dr. Leah Alexander, M.D., F.A.A.P.: “Eczema is associated with itching.

Often, babies with eczema rub their backs, arms, and legs against surfaces in an effort to scratch the affected areas, or repeatedly scratch the belly and chest.

This is a good way to distinguish heat rash from eczema.

Here is a link from the AAP about eczema that you may want to have a look at: https://www.healthychildren.org/English/health-issues/conditions/skin/Pages/Eczema.aspx

2) Baby Acne

Also common, and also harmless, baby acne is found in white-head pimples and red, raised bumps on baby’s face, neck, and back.

They are usually found in very small patches and when left alone will disappear within a couple of days without treatment.

Heat rash is not usually found on the face, but rather the groin, neck, armpits, and sometimes the chest.

3) Hand, Foot And Mouth Disease

This illness causes a blistering rash on the palms of the hands and bottoms of the feet.

Ulcers (white sores) in the mouth may also be present. Your baby may also get a fever.

This disease is contagious, but not very serious.

No treatment is required for this viral infection, and it should clear up within 7 days.

Heat rash is usually found in those “hidden” areas of the body, not on the extremities.

Note from Dr. Leah Alexander, M.D., F.A.A.P.: “Infants often get these lesions in the diaper area. I see this very often in clinical practice.”

4) Hives

Large, blotchy patches of red skin that are often triggered by allergic reactions.

Notice if they appear or get worse after your baby eats.

Heat rash will reduce in size and redness when your baby’s skin is cooled down. Hives will not respond to most heat rash remedies.

5) Diaper Rash

Diaper rash and heat rash are very similar, but diaper rashes caused by the brand of diaper won’t be solved with the home remedies below.

Try changing diaper brands if the rash is prolonged, in the diaper area, and unchanged with treatment.

Diaper rashes caused by sensitive skin will benefit from many of the remedies suggested at the end of this article.

6) Ringworm

This is a common skin fungal infection that appears in the distinct shape of circular rings anywhere on the body.

It is readily treated with prescription creams. Heat rash does not have a specific shape and will not appear in perfect circles like ringworm.

Things To Avoid Doing To Help Your Baby

1) Regular Baby Powder

Most baby powders can irritate the skin further, due to some of the chemical ingredients, not to mention that some claim it’s unsafe for it to be inhaled.

On the other hand, herbal baby powders may be safe, even beneficial.

Here’s one you can make at home.

Note from Dr. Leah Alexander, M.D., F.A.A.P.: “Corn starch baby powder is considered safe and effective.

Any powder containing talc is not, due to the inhalation risk that is mentioned in this section.

Fortunately, most companies who make powders for infants have removed talc, but it is still worth mentioning this so that parents know they need to avoid this ingredient.”

2) Broken Skin

Don’t apply anything to broken skin unless you are certain it won’t cause harm. Talk to your pediatrician if you’re not sure.

3) Too Many Layers

Avoid overdressing your baby.

Keep baby in lightweight, loose clothing or dress down to a diaper to give your baby’s skin a chance to cool down.

4) Car Seat

Keep baby out of their car seat as much as possible. The enclosed environment may cause overheating.

Try to get errands done during the cooler morning or evening hours, and keep them brief.

What To Do To Help Your Baby

1) Clean and Dry

The most basic (and free!) thing you can do is clean the area with water and let it air dry (WebMD says to avoid rubbing the skin with a towel since this can further clog pores).

A lukewarm tub or sponge bath would be ideal.

2) Cool Down

If you’re outside in summer heat, seek the coolness of air-conditioned indoors where possible.

At a family reunion with no indoor accommodations? Find a shady spot, lay down a blanket, and let baby rest without clothes on for a time.

If the baby is tired or wants to be fed but is already overheated, being snuggled up against your warm body is probably the last thing they want.

Try laying down beside baby to nurse with their body angled away from yours.

If it really is too hot and baby won’t settle down, it might be time to call it a day and head home to find relief.

After a bath, dress baby down to only a basic, loose layer of clothing or let her lay about in nothing but a diaper.

If the heat rash is in the diaper area, lay down a burp rag or cloth diaper down and let the baby go diaper free for periods of time throughout the day.

Babies can be overdressed even in the cold winter months; keep in mind that if you keep your home well-heated, your baby won’t need as many layers.

3) Be Prepared

If you’re planning a family vacation, like a day at the beach, hiking or camping, and you know it will be hot, be sure to have an escape plan if baby gets too irritable and hot.

An umbrella, a stop at an ice cream parlor (ideally indoors), or nap-time back at the hotel will make your trip much more enjoyable for everyone in the family.

4) Popsicles

Homemade 100% fruit juice or breastmilk popsicles are a sweet way for baby to keep cool. Just avoid anything with excess sugar added.

5) Vinegar Bath

In a shallow tub, add lukewarm water and a few splashes of vinegar. Sponge the affected area or let baby rest in the water for about 10 minutes. Avoid if the skin is broken.

Note: This is good for yeast rashes as well.

Do not leave baby unattended in the tub at any time or for any reason.

6) Chamomile

This soothing herb has antibacterial properties.

Steep a chamomile tea bag for ten minutes, let cool, and add to baby’s bath or apply with a sponge.

7) Marigold

Marigold, also known as Calendula, is an excellent natural remedy for heat rash, and there are dozens of baby safe creams and salves containing it.

8) Powder Up

Use a light dusting of cornstarch, arrowroot powder, or herbal baby powder to keep the area dry and aid in healing.

Avoid using too much powder; if it cakes, it could irritate the rash further.

If a yeast infection is suspected, don’t use cornstarch, as it can act as a food source for the yeast due to natural sugars found in corn.

9) Cold Compress

A washcloth wet with cold water feels great on a hot day.

Bonus tip: if your baby is teething, freeze a clean wet washcloth and let him chew on it!

10) Oatmeal

You can mix a handful of oatmeal with yogurt and spread this chunky paste over the rash to soothe it.

This is very messy, though, and we only recommend trying it if there’s nothing else on hand.

11) Aloe Vera Gel

Known for treating sunburn, Aloe Vera gel is cooling and provides instant relief for itching.

12) Change Laundry Detergents

There is always a chance your baby is having a reaction, especially if the skin irritation is a regular thing, and/or the rash appears on other parts of your baby’s body.

If you use a regular commercial laundry detergent, try switching to a more natural, chemical-free version.

What To Avoid Doing

1) Lavender Essential Oil

Lavender is thought to be cooling and reduce inflammation.

It’s for this reason that you’ll often hear recommendations to apply it on to the affected areas after diluting appropriately for your baby.

With that being said, this is best avoided, and here’s why:

Note from Dr. Leah Alexander, M.D., F.A.A.P.: “Lavender oil has been shown to cause early puberty and breast development in infants.

At my practice, we don’t recommend using it.

If you’d like to learn more about this issue, please have a look at this: https://www.endocrine.org/news-room/2018/chemicals-in-lavender-and-tea-tree-oil-appear-to-be-hormone-disruptors

2) Curash Powder

Some mothers swear by this powder’s almost magical ability to keep a heat rash dry and help it heal quickly – some claim it even worked overnight on the toughest of rashes.

With that being said, it does contain talc and fragrances, which are harmful for babies and should be avoided.

The talc found in Curash powder is just too dangerous for the lungs to be worth the risk.

3) Ointments

Bag Balm was created to be used on cow udders, but many human patients find great relief from the thick salve, due to the antibiotic ingredients.

As for Aquaphor, some moms swear by this over-the-counter cream.

Meanwhile, Vaseline creates a barrier between the affected skin and anything that might rub and irritate it.

With that being said, all of these ointments are best avoided, and here’s why:

Note from Dr. Leah Alexander, M.D., F.A.A.P.: “I have a concern about recommending ointments that can be occlusive to pores (which causes the heat rash in the first place).

Aquaphor, Vaseline, and Bag Balm are probably too heavy to be helpful.

Here’s an article from the Mayo Clinic if you’d like to learn more about this: https://www.mayoclinic.org/diseases-conditions/heat-rash/diagnosis-treatment/drc-20373282

Wrapping Up

As you can see, there are a lot of remedies for heat rashes that you can try safely at home.

Remember, if the rash doesn’t improve in a few days or other symptoms develop, call your baby’s pediatrician.

With the right care, your baby will find quick and effective relief from heat rashes.

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Medically Reviewed By: Leah Alexander, M.D., F.A.A.P.

Medically Reviewed By: Leah Alexander, M.D., F.A.A.P.

Leah Alexander, M.D. FAAP began practicing pediatrics at Elizabeth Pediatric Group of New Jersey in 2000. She has been an independently contracted pediatrician with Medical Doctors Associates at Pediatricare Associates of New Jersey since 2005. After graduating from Kalamazoo College and Michigan State University College of Human Medicine, she completed her pediatric residency at Overlook and Morristown Memorial Hospitals. She is board certified in General Pediatrics.

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