What causes heat rash?

Heat rash occurs when sweat becomes trapped under your skin.

Your sweat-producing glands are located in the middle layer of the epidermis. They can become clogged if you are wearing too much clothing (for example, when it is hot outside). Your anatomy can also predispose you to heat rash if you have folds or creases between areas of the skin where sweat can collect. Lotions and creams can clog the pores, along with the sweat glands, as well, producing heat rash.

What are the risk factors for heat rash?

A number of factors increase the risk of developing heat rash. Not all people with risk factors will get heat rash. Risk factors for heat rash include:

  • Excessive sweating
  • Hot, humid environments
  • Prolonged periods of inactivity, which permit sweat to collect and become trapped
  • Tight, constricting clothing that does not permit the skin to “breathe”

Reducing your risk of heat rash

Although you may not be able to control certain risk factors, such as living in a hot, humid climate, you can take some other steps to reduce your risk of heat rash.

You may be able to lower your risk of heat rash by:

  • Drinking plenty of water
  • Moving around to ensure sweat cannot collect in a certain area
  • Staying cool in hot weather by seeking shade or air-conditioned locations
  • Wearing loose clothing made with breathable fabrics such as cotton
INTRODUCTION

What is heat rash?

Heat rash is one of many different types of rash. Rash is a symptom that causes the affected area to turn red and blotchy and swell. The rash may cause spots that are bumpy, scaly, flaky, or filled with pus. Rashes can vary in location, pattern and extent and may occur in any area of the body.... Read more about heat rash introduction

SYMPTOMS

What are the symptoms of heat rash?

Symptoms of heat rash include the appearance of raised bumps on your skin in the affected area that may range in color from clear to red. The type and color of rash depend on the location in the skin where sweat glands are clogged, and symptoms have a range of severity. The mildest form is called miliaria crystalline (clear, raised rash), a blockage of the sweat glands at the top layer of the skin. Types that occur deeper in the skin include miliaria rubra (reddened rash) and miliaria profunda (larger and firmer bumps that are skin colored).... Read more about heat rash symptoms

TREATMENTS

How is heat rash treated?

The best way to treat heat rash is to ensure that you get plenty of air circulation around your skin. This means wearing light, loose clothing that will let your skin “breathe.” Staying cool and drinking lots of water can help minimize your symptoms and prevent heat rash from progressing to heat stroke.... Read more about heat rash treatments

Medical Reviewer: All content has been reviewed by board-certified physicians under the direction of Rich Klasco, M.D., FACEP. Last Annual Review Date: May 2, 2011 Copyright: © Copyright 2011 Health Grades, Inc. All rights reserved. May not be reproduced or reprinted without permission from Health Grades, Inc. Use of this information is governed by the HealthGrades User Agreement.

This Article is Filed Under: Skin, Hair and Nails


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