What is heat rash?

What is heat rash?

Heat rash is an inflammatory reaction to retained sweat in sweat glands. Sometimes the sweat glands get plugged up because of intense heat and humidity; there may also be accompanying bacteria or fungi involved.

There are three types of heat rash. The first type, Miliaria Crystallina, results in tiny vesicles, or blisters, near the outer edge of the sweat gland. The second type, Miliaria Rubra, is caused by blockage deeper down in the sweat glands, resulting in a redder, more inflammatory papular, or bumpy, rash. Finally, Miliaria Profunda involves blockage of an even deeper part of the sweat gland.

Dr. Lowell Goldsmith and Dr. Jeff Bernhard contributed their expertise on behalf of VisualDx for the above information.

Published on 07/06/2010 | Last updated on 10/18/2018