Erythromycin is a commonly used antibiotic and can be used by infants and children. Erythromycin ointment is mainly used for localized skin infections and can be used by infants and children, and can be used by babies as young as 10 months old. The prerequisite is that it is only useful for localized bacterial skin infections, but not for other fungi and so on, and it is also not effective for skin allergies and hives. The actual fact is that you can use erythromycin ointment topically on the perineum when there is a diaper rash secondary to a bacterial infection, and before using erythromycin ointment topically you must clean the area that needs to be coated and keep it dry before applying the medication. It is also necessary to use erythromycin ointment topically for at least 3-5 days before the effect is obvious enough for the course of treatment.