Many different types of creams and ointments are available that can both treat and help prevent diaper rashes. Miconazole is an antifungal product that is available over-the-counter (OTC). Although it is available without a prescription, it should not be used without the approval and supervision of your child's healthcare provider, and it should be used only for certain types of diaper rash, such as that caused by a yeast infection.
You may have to search beyond the baby section in the store to find many antifungal and corticosteroid creams and ointments. For example, miconazole is typically found in the women's vaginal yeast infection section.