Our 3 year old son was very recently diagnosed with SPD. We are still learning as we go. He has always, since infancy, "flapped" his arms when he is excited (stimming). However, he recently developed a "dry cough" that has become more and more repetitive throughout the day. Originally, it was just when he was excited - to go along with the flapping. But in the last few days, he is doing it all day long. It is about to drive us nuts. Is this common with SPD?