Heat Rash

  • Medical Author:
    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.

  • Medical Editor: Charles Patrick Davis, MD, PhD
    Charles Patrick Davis, MD, PhD

    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.

Quick GuideHeat Rash Pictures, Symptoms, Causes, & Treatments

Heat Rash Pictures, Symptoms, Causes, & Treatments

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. Continue Reading

Heat rash pictures

Pictures of heat rash in children and adults
Pictures of heat rash in children and adults
Reviewed on 11/3/2015
References
Medically reviewed by Norman Levine, MD; American Board of Dermatology

REFERENCES:

Rakel R. Textbook of Family Medicine. 8th edition. Philadelphia: Saunders/Elsevier. 2011

WebMD.com. Heat Rash Overview.

IMAGES:

1.iStock

2.iStock

3.iStock

4.Getty Images

5.iStock

6.iStock

7.Getty Images

8.Getty Images

9.Getty Images

10.Getty Images

11.Getty Images

12.Getty Images

13.Getty Images

14.Getty Images

15.iStock

16.iStock

17.iStock

18.iStock

Subscribe to MedicineNet's Skin Care & Conditions Newsletter

By clicking Submit, I agree to the MedicineNet's Terms & Conditions & Privacy Policy and understand that I may opt out of MedicineNet's subscriptions at any time.

VIEW PATIENT COMMENTS
  • Heat Rash - Describe Your Experience

    Please describe your experience with heat rash.

    Post View 57 Comments
  • Heat Rash - Symptoms

    What were the symptoms of your heat rash?

    Post View 7 Comments
  • Heat Rash - Treatment

    What was your heat rash treatment?

    Post View 11 Comments
  • Heat Rash - Home Remedies

    What home remedies have you tried for a heat rash?

    Post View 4 Comments
  • Heat Rash - Causes

    What are the triggers or causes of heat rash for you, a relative, or friend?

    Post View 2 Comments

Health Solutions From Our Sponsors