Heat rash (also called prickly heat) is a common problem in children, especially babies. It causes small red bumps on the skin. It appears most often on the neck, buttocks, and skin folds, but can appear anywhere on the body. Heat rash is not serious. It can easily be treated at home.
Heat rash is caused by blocked sweat glands. This can happen when your child:
Is exposed to too much sun or heat.
Is overdressed (wearing too many layers of clothing).
Engages in intense exercise or physical activity.
Heat rash can cause areas of the skin to turn red, develop small bumps, and become itchy.
Heat rash is diagnosed by how it looks. To get more information, the doctor will ask about your child’s symptoms and health history. The doctor will also examine your child. You will be told if any tests are needed.
In most cases, heat rash requires no treatment. It generally goes away on its own within 2 to 3 days. You can do the following at home to help relieve your child’s symptoms:
Apply over-the-counter (OTC) hydrocortisone cream 1 to 2 times per day to the rash to relieve itching. Don't apply the steroid cream under the diaper. Each time before and after applying the cream, wash your hands with warm water and soap.
Give your child OTC antihistamine medication to relieve itching.
Apply a cool compress (such as a clean washcloth dipped in cool water) to the rash.
Give your child cool baths.
Loosen your child’s diaper if it rubs against the rash area.
Contact the doctor if your child has any of the following:
A heat rash that doesn’t go away within 7 days of starting treatment
Other symptoms such as a fever, sore throat, or body aches, which may suggest an illness or infection
For fevers, call the doctor's office if your otherwise healthy child has any of the signs or symptoms described below:
In an infant under 3 months old, a rectal temperature of 100.4°F (38°C) or higher
In a child of any age who has a temperature that repeatedly rises to 104°F (40°C) or higher
A fever that lasts more than 24 hours in a child under 2 years old, or for 3 days in a child 2 years or older
A seizure caused by the fever
You can help prevent your child from getting a heat rash by:
Removing extra layers of clothing from your child when it’s warm. Children should not wear more than one extra layer of clothing than adults.
Dressing your child in loose-fitting clothing that does not rub against the skin.
Changing your child’s diaper right away when it’s wet or soiled.