Q&A: Do I Need To Wash My Nipples After I Feed My Baby?
No. Washing your nipples after (or before) feeding will only cause your nipples to become dry and irritated. Your breast milk actually contains many factors that inhibit the growth of bacteria and yeast and help provide natural protection to your nipple and your baby, so it’s okay to leave some of it on your nipples.
Be sure to gently wash your breasts along with the rest of your body during showering or bathing, but there's no need to wash your nipples any more often than that.