Prickly heat

Prickly heat (also known as heat rash or miliaria) is an itchy, red rash that often causes a stinging or prickling sensation on the skin.

It usually occurs when you sweat more than usual, for example in a hot or humid climate, but it can also occur in winter. See Causes of prickly heat for more information.

Excessive sweating can block up your sweat glands to become blocked, which can trap sweat beneath your skin. This causes irritation, and results in the rash.

The rash can occur anywhere on your body, but it most commonly affects areas that are covered by clothing.

Who is affected

People who are overweight or sweat easily are more likely to get prickly heat.

Babies and children are also more prone to prickly heat because their sweat glands are not fully developed.

Outlook

Prickly heat is not a serious condition, and rarely requires any specific treatment. Most prickly heat rashes will heal within a few days.