Since childhood i am very sensitive to desloratadine (makes me drowsy in an hour) while i am immune to loratadine. will i ever outgrow this?

Unknown: Actually the desloratadine is associated with less somnolence than the loratadine on a general basis. Certainly side-effects that we experienced as children may not be present as adults but there is not was to say with certainty that you will "out grown" it. If loratadine helps your symptoms and gives you fewer side-effects stick with that! Good Luck!