Heat Rash in Babies: Causes, Types and Treatments

Your baby’s skin can seem very sensitive and fragile, and many parents feel responsible if anything irritates it. A common skin condition in infants is heat rash. While this condition can sometimes cause discomfort to your baby, knowing the causes and treatment options can help you prevent, recognize, and treat it effectively. Here we explore what heat rash in babies is and its symptoms, causes, types, duration, treatments and prevention.

Heat rash in babies (also called miliaria, prickly heat, or sweat rash) is a skin condition that occurs when the eccrine glands and ducts in the skin that produce and release sweat are blocked.¹ This blockage causes small, red bumps or blisters or a pink rash on the skin that may be itchy or painful. These symptoms often occur in areas where sweat accumulates, such as the groin, neck, arms, chest, and upper back.^1.2 Heat rash rarely affects the baby’s face.¹

When babies’ bodies heat up and sweat, the sweat ducts can become clogged.² Babies have sensitive skin and a less efficient sweating system than adults, making them more susceptible to conditions that cause sweating and overheating.³ The most common causes of heat rash in babies include:

• Hot and Humid Conditions: Weather that causes sweating can lead to heat rash in babies.^1.2
• Fever: Just as warm weather can heat up a baby’s body and cause them to sweat, fever can also occur.⁹
• Ointment: Babies can also get heat rash in winter when creams or ointments applied to the skin cause blocked milk ducts and trap sweat. Lanolin ointment applied to the mother’s nipples while breastfeeding can also cause a heat rash in the baby if it transfers to the skin of the baby’s face and clogs its pores.² This could be confused with teething rash, a similar condition that is caused by saliva rather than sweat.⁴
• Tight clothing: Tight-fitting clothing or clothing that rubs against the skin can lead to blockage of the sweat ducts.^1.2
• Exercise: Heat rash can also occur in toddlers and older children when physical exertion causes sweating.²

There are three types of heat rash, each varying in severity and appearance. Heat rash is classified according to how deep the blockage occurs and how differently they occur:¹

Miliaria crystallina is the mildest and most superficial form of heat rash and appears as tiny, clear, fluid-filled blisters that resemble water droplets and burst easily. It generally does not cause any discomfort and can be quickly resolved with cooling measures.¹

This is the most common type of heat rash in babies. Miliaria rubra causes deeper blockage of the sweat ducts. Sweat penetrates deeper into the skin and causes an inflammatory reaction, which usually manifests itself in the form of redness. Inflammation causes the classic symptoms of heat rash, including red, itchy bumps and discomfort that can be worsened by increased sweating.¹

This is a rarer form of heat rash that occurs deeper in the layers of the skin. It typically occurs after numerous repeated episodes of miliaria rubra and in extremely hot environments and is therefore less common in babies than adults. Miliaria profunda presents as larger, flesh-colored bumps or cysts that may itch severely or have no symptoms.¹

The duration of a heat rash varies depending on the type, severity, and measures taken to treat it. In most mild cases, heat rash may resolve on its own within a few hours to a few days once the baby is moved to a cooler environment and his sweat glands are no longer blocked.¹ However, if the rash persists or worsens despite treatment, your baby develops a fever for no known cause, or the rash spreads or pus appears, indicating an infection, you should contact your child’s pediatrician.²

Remember that heat rash usually goes away without treatment.¹ To speed recovery, effective heat rash treatment focuses on relieving symptoms and preventing further sweating. Here are some methods you should consider:

The simplest home remedies for heat rash are to lower your baby’s temperature. Move your baby to a cooler, less humid environment. Dress them in light, breathable clothing and keep them in a well-ventilated room. You can try a cool washcloth or a lukewarm bath without soap to cool them down, but don’t let them soak in the cold for more than 10 minutes.² You can also use a fan to cool them down, being careful not to let their fingers come near the fan blades.

If your baby has a known cause of fever, such as a cold or another viral illness, Treatment of fever can help lower body temperature and thus treat heat rash. Tylenol (acetaminophen) and Motrin (ibuprofen) are the most commonly used medications to treat fever.¹⁰ If you are unsure which one or how much to use, contact your pediatrician’s office. Also contact us if you are unsure about the cause of the fever and/or rash.

Over-the-counter creams specifically designed for heat rash can help soothe the affected area. However, many of these creams are not suitable for young children. Therefore, consult your pediatrician before use. Here are some ingredients to look for in a heat rash cream for your baby:

• Aloe vera: This allows the skin to be cleansed, cooled, moisturized and disinfected. However, be careful not to apply too much and clog the sweat ducts.⁵
• Calamine: Calamine lotion can also be helpful for heat rash, but again, make sure it is safe for your baby’s age.²
• Hydrocortisone: For more severe cases of heat rash in babies, a mild steroid cream such as hydrocortisone cream for babies or triamcinolone (prescription) can relieve inflammation and itching. Be sure to use a cream and not an ointment, as this could clog the sweat ducts even further.^1.2

Similar to treatment, preventing heat rash is all about keeping your baby cool and comfortable to minimize sweating. Here are some practical tips to prevent heat rash:

Choose lightweight, breathable fabrics such as cotton for your baby’s clothing. Cotton and other natural fabrics absorb moisture and keep skin cool and dry.⁶ Do not dress your baby in clothes that are too tight and wear light-colored clothing that does not retain heat on your baby’s body.⁷

Make sure your baby drinks plenty of fluids to stay hydrated. Proper hydration can help regulate body temperature and reduce sweating. Babies under 6 months should only consume breast milk or formula to maintain hydration. However, in hot temperatures they may require more milk than usual.⁷

If possible, keep the environment cool. If air conditioning is not available, use fans and keep the room well ventilated.⁶ Also, make sure to cool the car – my babies always sweat so much in the car in the summer because the air conditioning doesn’t reach them right away. If possible, start your car and run the air conditioning for a minute or two before buckling it into the hot car seat. Remember: Never leave a baby alone in a parked car, even if it is cool outside!⁷

Keep your baby out of direct sunlight (especially during the hottest times of the day) to avoid overheating. It’s best to keep them in the shade or wear UV-protective hats and clothing if possible.² If they must be in the sun, use a light mineral Baby sunscreen this won’t clog your pores.⁸

5. Avoid ointments and powders

Ointments and other oily and thick skin products, such as those used to treat another skin condition mentioned eczemacan clog sweat glands and worsen a heat rash.² It was once thought that baby powder would absorb moisture, but it doesn’t prevent heat rash. It can actually clog pores and trap heat, causing heat rash in babies.⁶

Give your baby lukewarm baths to cool the skin and remove sweat if he or she is overheated. Avoid harsh soaps or bubble baths, which can further irritate the skin. Although exfoliation is not recommended for babies’ skin, regularly rinsing and cleansing your baby gently can help prevent the buildup of sweat and skin debris that clog sweat glands and cause a heat rash.²

Heat rash in babies can occur regardless of your efforts to prevent it. Fortunately, it is usually mild and goes away on its own within hours to days. While it may cause temporary discomfort and stress to your baby, it usually does not pose a serious health risk. Understanding the signs, symptoms, prevention and treatment can help you Effectively treat and manage heat rash in your baby. Regular cooling, proper clothing, and awareness of environmental factors are key to preventing and relieving this condition. If you have concerns or your baby’s heat rash persists despite home remedies, contact your pediatrician. The best way to ensure your baby stays comfortable on hot and humid days is to ensure your baby stays comfortable and cool.