Question: how to treat yeast infection while nursing?
Answer: Topical azole antifungal ointment or cream (miconazole and clotrimazole also inhibit the growth of Staphylococcus (bacteria) on nipples. [ii]
Nystatin suspension or miconazole oral gel for infant's mouth. ... 
Gentian violet (less than 0.5% aqueous solution) may be used daily for no more than 7 days.