Breast itching is not uncommon. Although it is not typically a sign of breast cancer, any breast symptom should be evaluated by a healthcare provider to be sure.
Itching may develop following breast surgery or cancer treatment. But assuming you have not had previous breast problems, it may be a sign of dry skin or minor inflammation. Using a good moisturizer such as Lubriderm® can help.
If the itching is truly “inside,” it might be helpful to stop caffeine. You can also try an herbal supplement called evening primrose oil, 1000 milligrams twice a day for three to four months, to try to “calm down” breast tissue.
The one thing I would worry about is if the nipple itself looks abnormal — reddened, flaky or ulcerated. A rare form of breast cancer, called Paget’s disease, can present in this way and may cause itching.