Disease Information

What is Prickly Heat?

Prickly heat is a skin rash caused by sweat trapped in the skin. Normally, sweat travels to the surface of the skin through tiny ducts. If the ducts become narrowed or clogged, the sweat is trapped in the skin. This can cause redness, itching, and small blisters. The rash often appears on the torso and thighs, especially where skin touches skin. Prickly heat tends to be more common in hot, humid climates.

Symptoms of Prickly Heat

The symptoms of prickly heat are fairly straightforward. Red bumps and itching occur in an area where sweat has been trapped underneath layers of skin.

The neck, shoulders, and chest are the most common places for prickly heat to appear. Folds of skin and places where your clothing rubs against your skin are also areas where prickly heat might occur.

Symptoms can occur a bit differently in each person. They can include:

• Itching
• Irritation that feels like prickling
• Small bumps or blisters
• Large, red areas of skin
• Sweating profusely
• Fatigue
• Extreme thirst Fast pulse
• Red miliaria Rubra
• Darker urine and going less often
• Pale skin
• White/Yellow miliaria pustulosa
• Feeling sick or being sick
• Clear miliaria crystallina
• Dizziness

The symptoms of prickly heat can be like other health conditions. Make sure to see your healthcare provider for a diagnosis.

Sometimes prickly heat will take the form of a patch of very small blisters. This is your skin reacting to the sweat that’s leaked between its layers. Other times the area of your body where sweat is trapped might appear swollen or itch persistently.

Causes of Prickly Heat

The condition is caused by narrowed or clogged sweat ducts. This may be because of things that cause sweating, such as:

• Hot, humid weather
• A lot of physical activity
• Illness with fever
• Tight or warm clothing
• Bandages
• Medicine patches that stick to the skin
• Health conditions that cause extra sweating (hyperhidrosis)

It may also be from:

• Bacteria
• Some medicines, such as isotretinoin or beta blockers

Prickly Heat on a Baby

Children, especially infants, are especially vulnerable to prickly heat. Their sweat glands aren’t yet fully developed, and their skin isn’t used to rapidly changing temperatures.

Infants tend to experience prickly heat on their face and in the folds of their skin around the neck and groin.

Like most baby rashes, prickly heat is usually harmless and will go away on its own. Your baby might act cranky and be difficult to soothe while they’re experiencing the itchy sensation of heat rash.

If you notice a small patch of tiny red blisters beneath your child’s skin, evaluate their surroundings. Are they wearing too many layers? Is their clothing appropriate for the temperature?

Is your baby acting restless, and does their urine indicate they could be dehydrated? A cool bath will provide relief for your child in most situations. Keep their skin dry when it’s not bath time. Avoid oil-based products, as they could clog the pores further.

How is Prickly Heat Diagnosed?

Your healthcare provider will ask about your symptoms and health history. They will give you a physical exam. The physical exam will include looking closely at your skin.

If you have severe symptoms, your healthcare provider may do a skin biopsy. They will remove a small piece of skin to send to a lab.

What are possible Complications of Prickly Heat?

In rare cases, blocked ducts may cause damage to sweat glands. This is called miliaria profunda. The sweat glands stop working (anhidrosis). This causes problems with the body cooling itself normally with sweat. You can then be more easily overheated (hyperthermia).

How is Prickly Heat Treated?

Treatment will depend on your symptoms, your age, and your general health. It will also depend on how severe the condition is.

The rash usually goes away on its own when sweating is prevented. You can do this by:

• Keeping your skin cool and dry
• Wearing lightweight, loose clothing
• Wearing fabric that lets air get to the skin, such as cotton
• Removing bandages or patches

Other treatment may include:

• Using a gentle exfoliator in the bath or shower
• Corticosteroid cream or lotion to help reduce itching and inflammation
• Antibiotic cream or lotion if bacteria is part of the cause
• Drying powders

Talk with your healthcare providers about the risks, benefits, and possible side effects of all medicines.

Prevention Tips

The most effective way to avoid prickly heat is to stay away from situations that cause excessive sweating. Try these tips:

• Wear loose-fitting cotton clothing if you know you’re going to be in a hot or humid climate.
• Take cool baths or showers frequently if you’re visiting a hot or humid climate.
• If you’re in a hot or humid climate, spend a few hours each day in a cool space with fans or air conditioning.
• Opt for lightweight bedding, such as cotton or linen sheets.
• When you exercise outside, choose gear that’ll wick moisture away from your skin.
• Make sure to change out of sweaty or wet clothing right away after experiencing intense heat.
• Change your baby’s diaper immediately after they wet or soil it.
• Stay well-hydrated by drinking plenty of fluids.

Key Points about Prickly Heat

• Prickly heat is a skin rash caused by sweat trapped in the skin. It tends to be more common in hot, humid climates.
• Symptoms include redness, itching, and small blisters.
• The condition is caused by narrowed or clogged sweat ducts. This may be from things that cause sweating, such as hot, humid weather or physical activity.
• The rash usually goes away on its own when sweating is prevented. You can do this by keeping your skin cool and dry.
• Treatment may also include corticosteroid cream or lotion to help reduce itching and inflammation.

Next Steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.
• Before your visit, write down questions you want answered.
• Bring someone with you to help you ask questions and remember what your provider tells you.
• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.
• Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are.
• Ask if your condition can be treated in other ways.
• Know why a test or procedure is recommended and what the results could mean.
• Know what to expect if you do not take the medicine or have the test or procedure.

Reference:

https://www.healthline.com/health/prickly-heat#prevention-tips

https://www.cedars-sinai.org/health-library/diseases-and-conditions/p/prickly-heat.html