Suggest Treatment For Impetigo In A Child

My almost 5 year old grand daughter has a skin condition on her face. The Dr s are saying it is impatigo. It is not scabby, but looks red almost like a fungus. She has allergies and asthma. They have treated her with antibiotics etc. The color is between pink and light red and around her mouth and under nose. Is there something they could be missing. She also had allergic reaction to peaches. Someone had eaten a peach she came in contract with. They treated her for that first and then said it turned into ipatigo.