The best way to deal with a breast rash is to reduce the accumulation of sweat around the breast area. Place a thin piece of cotton between the lower part of your breasts and the skin underneath to absorb moisture and create a barrier. You can also use soft paper towels or dinner napkins. Also, wear lightweight clothing, preferably made of cotton or natural fibers that help absorb moisture and keep your body sweat free.
Mix one-half cup of white vinegar in half a bucket of hot water. Use it to wash all your bras and dry them in direct sunlight. Another option is to apply apple cider vinegar on the irritated skin. Wash the infected area with mild soapy water, rinse with cold water and pat dry. Mix one teaspoon of apple cider vinegar in a cup of water and apply it to the affected area. Do these two or three times daily. If it causes discomfort, stop using it.
Coconut oil has a soothing and healing effect on skin that helps provide relief from rashes. Plus, due to its greasy nature, it will help reduce friction that causes rashes under breasts and also avoid infections, thanks to its antibacterial and antifungal properties.