Thank you for your question. A rash is a tricky thing to diagnose (find the cause) because there can be many different reasons why it’s occurring. Talk to your health care provider and ask about seeing them in person or with a photograph or “virtual visit” during these COVID times.
Here are a few reasons why you may have developed a rash: irritation from a bra because it is too tight or the fabric or lace is scratchy, or allergies to the chemicals used to make the bra, or to the detergent or fabric softener you are using. Sometimes, stretch marks initially look like red spokes on a wheel. If your breasts have grown a lot in the past year, this might be a cause. For starters, take a look at your bra, does it fit correctly? An ill-fitting bra (one that doesn’t fit right) can cause a lot of different problems such as back pain, shoulder indents (from your straps), pain with exercise, bruising, red marks, and rashes either under or on the side of your breasts. An easy way to make sure your bra fits correctly is by getting measured. Most major department stores have sales associates who are specially trained in taking measurements. This will help choose the right bra.
Another thing to keep in mind is the temperature is beginning to rise as we begin to enter summer. In the summer months, our bodies produce more sweat, which escapes through our glands. Many people get a heat rash. A great way to prevent a heat rash is by wearing moisture wicking materials, usually used in sports bras and athletic wear. Also use a sunscreen that is water-proof or sports-proof.
Again, remember only your health care provider (HCP) can diagnose and treat your rash. It’s important that you talk to your HCP and get it checked out.