The reason for giving the antibiotics for ten days is to make sure that the infection has been cleared. While it is true that some people probably clear the infection with less than ten days of antibiotics, most studies have shown that the best clearance rate for the most people occurs after ten days. There is no way to know ahead of time if your child will clear the infection sooner, so it is best to follow your doctor's recommendation and give it for the full ten days.

If the infection is inadequately treated, it can come back again, "smolder" in a milder fashion for a while, or cause serious complications.