The nipple helps nourish the baby. Small openings around the nipple are part of a gland that makes oil to keep the skin soft. Cracked nipples usually happen to breastfeeding mothers. Sometimes a sore will form. Cracked nipples are a skin condition that is caused by damage to the nipple. Sometimes cracked nipples can be seen three to seven days after the baby is born. If a nipple appears to be in the shape of a wedge or it looks white and flat this can mean that the nipple may form cracks.