Heat Rash (cont.)
Benjamin Wedro, MD, FACEP, FAAEM
Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.
Charles Patrick Davis, MD, PhD
Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.
In this Article
- Heat rash facts
- What is heat rash?
- What are the causes of heat rash?
- What are the symptoms of heat rash in children and adults?
- Who is at risk for heat rash?
- What does heat rash look like?
- Heat rash pictures
- How is heat rash diagnosed?
- What is the treatment for heat rash?
- Home remedies for heat rash
- Medical treatment for heat rash
- How can heat rash be prevented?
- How effective are electric fans in preventing heat rash?
- How can people protect their health when temperatures are extremely high?
- How much water should I drink in hot weather?
- Should I take salt tablets during hot weather?
- What is the best clothing for hot weather or a heat wave?
- What is the prognosis for heat rash?
- Pictures of Heat Rash - Slideshow
- Pictures of Summer Skin Hazards - Slideshow
- Pictures of Dehydration Tips - Slideshow
- Find a local Doctor in your town
Who is at risk for heat rash?
Newborns, infants, the elderly, and obese individuals with large areas with skin-on-skin contact areas (for example, a large overlapping area of abdominal fat) are at risk for developing heat rash. They all are especially at risk if they are immobile for long periods of time and parts of the skin aren't exposed to circulating air, which results in the inability of the sweat ducts to "breathe" (evaporative cooling).
Heat rashes are more common in places with hot, humid, climates because people sweat more.
Intense exercise associated with lots of sweating may cause a heat rash, especially if the clothing worn does not allow adequate air circulation.
What does heat rash look like?
The appearance of the heat rash depends upon where the excess sweat gets deposited in the skin.
Tiny blisters that look like small beads of sweat are seen if the sweat is blocked at the most superficial layers of the skin where the sweat duct opens on the skin surface. Called miliaria crystallina, it has no symptoms other than these "sweat bubbles."
Classic heat rash or miliaria rubra occurs if the sweat causes inflammation in the deeper layers of the epidermis. Like any other inflammation, the area becomes red (and therefore the name rubra = red) and the blisters become slightly larger. Because the sweat ducts are blocked and don't deliver sweat to the skin's surface, the area involved is dry and can be irritated, itchy, and sore. This rash is also called prickly heat.
Less commonly, after repeated episodes of prickly heat, the heat rash may inflame the deeper layer of the skin called the dermis, and cause miliaria profunda. This rash is made up of larger, harder bumps that are more skin colored. The rash begins almost immediately after exercise, and again no sweat can be found on the affected areas. Rarely, this type of heat rash may be potentially dangerous if enough skin is involved, since the lack of sweating can lead to heat-related illnesses like heat cramps, heat exhaustion, or heat stroke.
Heat rash pictures
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