4 week son has thrush. Do I have to wash the nystatin cream off my nipples before he feeds?

I've been on antibiotics for 3 weeks trying to get rid of my mastitis and now just as its healed, my sons got thrush. My doctor prescribed nystatin for my nipples and his bum, but is it ok if the nystatin cream (not ointment) gets in his mouth? in pain... help!4 week son has thrush. Do I have to wash the nystatin cream off my nipples before he feeds?
When my daughter had thrust I used the same nystatin used for her mouth on me, therefore it did not have to be washed off, I have never heard of a cream though. In my experience the Nystatin did not work well, I tried an over the counter called Blue Violet and it worked great!!