The first possibility is that you may be suffering from flat warts, which are a relatively common condition, mostly caused by the human papilloma virus, and need to be treated with medication. The second is a tumor, which is less common and includes intraductal papillomas and lipomas, and requires ultrasound examination and, if necessary, puncture pathology and surgery. The third type, which may be due to bacterial infection and inadequate breast cleanliness, is nipple folliculitis, which can be associated with pain. The fourth, which may be suffering from nipple acral warts, will also be itchy and unbearable. In addition, there may be hyperplasia of the nipple, etc. Other possibilities lead to it, and it is best to visit a hospital breast specialist to clarify the cause and then receive the appropriate treatment according to the cause.