Butt rash cure?

my son has had a butt rash every since he has been in the hospital and the nurses says its part of being a newborn. its so red that its peeling like a blister. i dont use baby wipes with alcohol or any other fragrance just use warm wash cloth. i have been putting destin on his butt where its red but still do no good. his first doctor appointment is next friday with his pediatrician. he is 1 week old today. i have had his diaper off of him all day to let air hit his red rash. any suggestions on a different cream or a remedy?