I have one old reference in The Womanly Art of Breastfeeding ( 3rd ed) that
suggests bathing the nipples in vinegar and water post nursing. I believe
there are also references to vinegar and dietary changes in a book called The
Yeast Connection. For severe cases I have recommended that mother read The
Yeast Connection. The dietary restrictions are somewhat severe so I always
warn the mom tho glean the book for information and start with the least
restrictive diet first.