Chest Rash After Running

If the run you recently enjoyed left you with an itchy chest rash, you are in good company – rashes are surprisingly common among runners, says “Marathon and Half Marathon” author Sam Murphy 1. There are many possible causes for your chest rash. Check with a doctor to get an accurate diagnosis and to check for medical conditions that may cause rashes.

Heat Rash

Heat rashes are common among runners. You may experience one on your chest or elsewhere on your body, Murphy notes. This rash may be prickly feeling or intensely itchy. According to Medical News Today, you can help prevent heat rash by wearing lighter clothing and by taking showers in cool water 3.

Sweat Rash

Sweat rashes, in which your sweat ducts become obstructed, may cause itchy bumps on your chest. Sweat rashes may be caused by an increase in normal Staphylococcus epidermidis bacteria living on your skin. These produce a sticky substance that can block your sweat ducts, according to the New Zealand Dermatological Society 4. When your sweat leaks through the walls of the sweat duct behind the block, you get spots that can range in severity from tiny blisters to red lumps that are extremely uncomfortable. In some cases, pustules can form and become infected. Prolonged exposure your skin to sweat can cause the same effect that a rise in Staphylococcus epidermidis does, note the experts at the society. Minimize risk by showering immediately after you run, by wearing clean clothing and using sweat-wicking fabrics, recommends Murphy.


Your rash may be caused by chafing. If you are a woman, your sports bra may contribute to this problem. Shirts with slik-screened designs across the chest also can increase chafing risk. Minimize chafing by wearing soft and loose-fitting clothing and by using petroleum jelly in problem areas. Be careful with this solution, however, because ointments can block your pores, raising your risk for other types of rashes.

Contact Dermatitis

Contact dermatitis may be the root of your chest rash problem following a run. The laundry detergent, fabric softener, soap or lotion you use may be responsible. Dyes or chemicals in your clothing also may be a cause. If you suspect contact dermatitis, eliminate any new products that you use on your clothing or skin. To minimize risk for contact dermatitis, use a nondrying soap that does not have dyes or fragrances as well as fragrance-free laundry products.