What is a Heat Rash?

Heat rash is a skin condition which is characterized by a reddish, pimply rash which is especially common in the folds of the skin or around tight waistbands and clothing. It is caused by excessive heat, which clogs the sweat glands of the body. Although this type of rash is not inherently dangerous, it does suggest that the patient may be getting dangerously hot. In addition to treating the heat rash, it is important to take steps to ensure that the condition does not happen again.

You may hear a doctor refer to a heat rash as milaria. Other people call the condition a sweat rash, in a reference to the blocked sweat glands, or they term it “prickly heat,” in a reference to the faintly itchy, prickling sensation which accompanies the rash. Astringents like witch hazel can help to relieve the itching, while cooling ice compressed may relieve the heat which is causing the rash to appear. Milaria can be prevented by staying clean and cool, with the assistance of regular showers, air conditioning, and fans.

Infants and young children are especially susceptible to heat rash, both because they have under-developed sweat glands and because they cannot dress themselves or vocalize about feeling too hot. Since most parents want to keep their infants warm, they may err on the side of caution and get their children too hot. Runners may also get heat rash, as do people in hot, humid climates.

Ultimately, the rash will go away once the body has had a chance to grow fresh cells around the sweat glands. If it does break out, regular cool showers with mild soap are an excellent idea, since they will keep the affected skin clean and reduce the risk of infection. Oil-free lotions can help to control the itching associated with a heat rash, and doctors may prescribe antibiotics or antiseptics to prevent bacterial colonization of the delicate skin.

A basic heat rash is called milaria rubra. Should the skin become infected, it is termed milaria pustulosa, and it requires more aggressive medical treatment. It may also be more painful for the patient. A recurring case is known as milaria profunda, and it should be addressed by a doctor, since it indicates that the patient's body is getting too hot on a regular basis. This can be extremely dangerous or even fatal if it turns into heat stroke or heat exhaustion.