Is breast feeding with nipple eczema harmful?

You have not stated the age of the infant. The skin around the nipple must be cleaned with warm water and cotton to remove all traces of the ointment/medication and then the breast milk expressed in a pre boiled cup/katori and fed with a spoon to the infant. The infant must not be denied the advantages of breast milk because of a skin infection. The breast milk will NOT transmit eczema to the infant.