There are two kinds of heat rash -- that which forms in the folds of the skin, where moisture and friction combine to make the skin raw, or "prickly heat" -- when lots of bumps are caused by blocked sweat glands. How you treat your bout of heat rash depends on the type you have.
Treating Heat Rash in Folds of the Skin
Moisture is the enemy when heat rashes form in folds or creases in the skin. As the skin moves and rubs against itself, it becomes raw and irritated. Moisture makes the irritation worse. The medical name for this type of rash is intertrigo.
To add insult to injury, raw skin is vulnerable to infections from fungus, yeast or bacteria. The heat and the moisture make those same folds of the skin perfect places to grow all three.
Treatment for heat rashes caused by friction is based on reducing friction and reducing moisture.
- Drying agents, like talc or baby powder, will make the area feel better.
- When possible, let the area get some air -- preferably dry, cool air.
There are some problem areas that are prone to friction heat rashes: under the breasts, armpits, fat rolls, between the thighs, between the toes and between the butt cheeks.
Babies are prone to these types of heat rashes because they have cute little fat rolls and diapers, which trap moisture. This is what we call a diaper rash. Using baby powder works for babies, and it works for adults, too.
If a friction heat rash gets infected, it may be time to see the doctor. Some infections are very common, such as athlete's foot or a yeast infection. Others are less common, but can be even more dangerous, like a staph or MRSA infection. Look for:
- White or light coloring over the red rash
- Flaking skin
- Pus oozing from the rash.
- Blisters or boils
Treating Prickly Heat
The other type of heat rash is called prickly heat. Sweat can't escape through blocked ducts, causing lots of little skin bumps. Prickly heat is found mostly on the legs, chest, arms and back. It's often made worse by being covered up.
Treatment for prickly heat is all about cooling off:
- Uncover the area.
- Get out of the heat.
- Rinse off with cool water.
Preventing either kind of heat rash involves the same tips recommended for treatment. In other words, whatever works to make a heat rash better is likely to prevent it in the first place.
Janniger, C.K., et al. "Intertrigo and common secondary skin infections." Am Fam Physician. 2005 Sep 1;72(5):833-8.
O'Connor, N.R., McLaughlin, M.R., and Ham, P. "Newborn skin: Part I. Common rashes." Am Fam Physician. 2008 Jan 1;77(1):47-52.