Perspiration is the body’s way of regulating internal temperature. As sweat evaporates, it cools the surface of the skin. But when the sweat ducts become blocked, this mechanism ceases to be effective, causing localized overheating and the development of an itchy rash. Not surprisingly, heat rash usually develops in areas which are not exposed to open air and are generally covered by clothing, even in warm weather, such as the groin or underarms. The condition is uncomfortable but not serious, and the worst of the symptoms can be alleviated with a few simple home remedies.
The first step in treating a heat rash is to cool the affected areas of the body. In this case, the armpits need to be uncovered and the temperature of the skin must be reduced. Place a chair directly beneath an air conditioning vent or in front of a fan, lean back and place your hands behind your head, allowing the cooler air to pass over the rash. Once the rash has begun to cool off, consider sponging the area with cold water or taking a cold shower. Alternatively, you can wrap a bag of frozen vegetables in a towel and hold it under your arm, being sure to cover the affected area completely. Hold the “ice pack” in place for 15 minutes, repeating every two hours if necessary.
Once the skin has been cooled, search your kitchen for baking soda, cornstarch or instant oatmeal. You can stir 1/4-cup of oatmeal into a tub of cool water and soak in it for up to 30 minutes to help reduce itching. You can also add baking soda to your bath or apply a light dusting to your skin; as it will help keep excessive perspiration from building up in the armpit area. Cornstarch is also an acceptable dusting powder or it can be mixed with water, forming a thick paste that can be spread over the rash. The paste should be allowed to dry for at least 20 minutes and then wiped away with a damp towel. If you must use a deodorant or antiperspirant while trying to treat heat rash, choose an aerosol and apply it after you’ve taken care of your skin.
After these remedies have been applied to your heat rash, do what you can to keep air circulating around the affected area. Choose loose-fitting clothing made of absorbent materials, such as cotton, and do not cover the rash with bandages of any kind.
If your rash does not clear up after two weeks of self-care, if you begin to develop white pustules in the affected area, or if the rash is getting noticeably worse rather than better, seek professional medical advice. This may indicate a more serious condition such as psoriasis.