Sweat rash, also known as prickly heat, heat rash or miliaria, is a very itchy and unpleasant condition that commonly occurs when we sweat a lot in hot and humid conditions. Excessive sweating can cause the sweat glands to become blocked with bacteria and dead skin cells, which stops them from emptying properly. This causes the sweat to get trapped under the skin, creating a spotty red, prickly rash.

The condition is common amongst athletes, the physically active and anyone sweating more than they usually do. Bad cases can lead to an imbalance of natural fungi on the skin, leading to candidal intertrigo (infected sweat rash). Prickly heat is also widespread in babies and young children because their sweat glands are less developed and more prone to blocking.

As heat rash is, in essence, an allergic reaction, taking an antihistamine can help reduce the chances of an outbreak. Antihistamines work by blocking the action of histamine, a substance released by the body as a reaction to allergens. The release of histamine begins a chain reaction that leads to the release of other chemicals that add to the allergic response, a typical result of which is itching.

An itch-reducing preparation, such as calamine lotion, can help calm the maddening urge to scratch. When the skin is sore and inflamed, a mild (1%) hydrocortisone cream will help soothe the irritation.

If you are prone to outbreaks of heat rash, using an antibacterial soap when you bath or shower is a good idea. It may help clear the pores and prevent the blockage that can lead to the sore, prickly skin associated with the condition.

If you would like further information on sweat rash, please visit our Sweat Rash Information page.