The breast pain you describe fits the pain of nipple and/or ductal
infection with Candida. The fact that it improved with fluconazole
(Diflucan) supports this.
Unfortunately, the course of treatment the mother had is usually
inadequate to treat this problem, and the one dose, or a few days
treatment is probably leading to increased resistance of Candida to
fluconazole. In my experience, it takes 100 mg twice daily for *at
least* two weeks to treat and prevent recurrence of Candida associated
with breastfeeding. Sometimes longer than that.
Jack Newman, MD, FRCPC