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Heat rash is usually harmless, but can be itchy.

Heat rash is usually harmless, but can be itchy.
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Heat rash

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).

Last reviewed: September 2017

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Heat rash or prickly heat: babies & kids | Raising Children Network

Heat rash, prickly heat or miliaria looks like little red spots on the skin. It might appear if your child gets too hot. Its common and easy to treat.

Read more on Raising Children Network website

Parenting and Child Health - Health Topics - Intertrigo (heat rash)

Intertrigo is a rash which occurs inside skin folds, where two surfaces of the skin press on or rub on each other, such as under the chin of a baby, under the armpit or in the nappy area. The skin in these areas may be damp much of the time, and can develop a rash. This rash is called intertrigo. It is also sometimes called a heat rash.

Read more on Women's and Children's Health Network website

Miliaria - ACD

Miliaria is a group of skin conditions that arise from blockage of sweat ducts. There are three types of miliaria classified by the level of blockage of the sweat duct.

Read more on Australasian College of Dermatologists website

Babies in hot weather

How to keep your baby safe in hot weather with tips on sun safety and keeping cool, avoiding dehydration and heatstroke, plus links to trusted resources.

Read more on Pregnancy, Birth & Baby website

Rashes

Trusted information on the different types of baby skin rash, meningitis warning signs, plus links to trusted resources.

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