What is heat rash or prickly heat?
Sometimes called miliaria, this is a harmless but very itchy skin rash with small red spots in places where sweat collects, such as the armpits, back, under the breasts, chest, groin, crooks of elbows and knees, and the waist.
This happens when your body sweats more than usual, so it’s usual to get it during the summer months or whilst on holiday in a hot climate. It is caused by a blockage and inflammation of sweat ducts in heat and high humidity, which causes:
- tiny red spots
- an irritating itch and prickling sensation
- redness and mild swelling of the affected area.
Miliaria is common in newborn babies as their sweat glands haven’t developed properly yet.
Symptoms of heat rash last two to three days and generally clear up without any further treatment. However, you will need treatment if the rash gets infected.
Speak to your pharmacist for advice on medicines available to ease the symptoms of itching.
Read more about other summer skin rashes.
Not sure what to do next?
If you are still concerned about your heat rash, why not use healthdirect’s online Symptom Checker to get advice on when to seek medical attention.
The Symptom Checker guides you to the next appropriate healthcare steps, whether it’s self care, talking to a health professional, going to a hospital or calling triple zero (000).
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Last reviewed: September 2017