Topic Overview

What is heat rash?

Heat rash (prickly heat ) is a red or pink rash usually found on body areas covered by clothing. It can develop when the sweat ducts become blocked and swell and often leads to discomfort and itching. Heat rash is most common in babies, but it may affect adults in hot, humid climates.

What causes heat rash?

In babies, heat rash can be caused by well-meaning parents who dress their baby too warmly, but it can happen to any baby in very hot weather. A baby should be dressed as an adult would be to be comfortable at the same temperature and activity level. Babies' hands and feet may feel cool to your touch but that does not mean they need to be dressed too warmly in hot weather.

What are the symptoms of heat rash?

Heat rash looks like dots or tiny pimples. In young children, heat rash can appear on the head, neck, and shoulders. The rash areas can get irritated by clothing or scratching, and, in rare cases, a secondary skin infection may develop.

How is heat rash diagnosed?

Heat rash can usually be identified by its appearance and does not usually require medical attention. But if it doesn't go away after 3 or 4 days, or if it appears to be getting worse, or if your child develops a fever, contact your doctor right away.

When you or your child has a rash, be sure to watch for signs of infection, including:

• Increased pain, swelling, redness, or warmth around the affected area.
• Red streaks extending from the affected area.
• Drainage of pus from the area.
• Swollen lymph nodes in the neck, armpit, or groin.
• Fever of 38°C (100.4°F) or higher, or chills with no other known cause.

If any of these symptoms develop, contact your doctor immediately.

What is the treatment for heat rash?

Most prickly heat rashes heal on their own. The following steps can help relieve symptoms.

• Start by removing or loosening your baby's clothing and move him or her to a cool, shady spot.
• Give your child a lukewarm bath with non-drying soap.
• Let the skin air-dry instead of using towels.
• Avoid ointments or other lotions because they can irritate the skin.

The following tips can help prevent future episodes of the rash:

• Dress your child in as few clothes as possible during hot weather.
• Choose loose-fitting, light cotton clothing.
• Keep the skin cool and dry.
• Stay in a well ventilated, cool (16 to 20 degrees Celsius) environment.

After the rash is gone, gradually expose your child to warmer temperatures so that his or her skin can acclimate.