I have a friend here at the university who has asthma and keeps a spare inhaler in his strad case, I've never seen him pull it out though. Boy he can play, beautiful tone, and all through the scale...we read Paganini's Caprice No. 24 a couple of days ago, varying tempos and range issues, and he was completely fine, played every note. His asthma doesn't appear to be so severe though. He told me that it came about because he used to run a lot, and burned his lungs running in the cold, or something to that effect. I doubt trumpetting/cornetting could hurt, and I'm sure the feedback vibrations would help in some way. Besides, music is a good mood elevator and higher mood status' have been proven to increase a person's health.