Hi, I have gone through your question. The yellow crusty spots on the nipple are nothing but the colustrum which has come out. Colostrum is the first milk which come out from the breast after the baby is born. It is rich in fats, hence yellow. I assure you not to worry as it will not cause any problem and please don t try to remove them as then a potential site of infection will be open. Hope you found this answer helpful. Wishing you good health.