Sometimes a milk blister can be mistaken as mastitis. Also known as a bleb, a milk blister is a painful white dot on the nipple or areola caused by blocked milk flow towards the opening of the nipple or skin overgrowth at the opening of the duct. Milk blisters can be resolved over a few weeks without any treatment.
Your doctor may also evaluate if you have symptoms that indicate a different disease such as inflammatory breast cancer. This rare form of breast cancer causes redness and swelling that can be mistaken for mastitis. To get an accurate diagnosis, your doctor may recommend a mammogram and/or ultrasound, as well as a course of antibiotics. If symptoms persist after treatment, you may additionally need a biopsy to make sure you don’t have breast cancer.