M.P.
My granddaughter is now 11 and has gotten asthma with every cold since she was a baby. Still does some times. She is on a daily inhaled steroid (past 2-3 years) which does seem to help her be less prone to asthma attacks and she's had no negative side effects.
The reason a cold triggers an asthma attack is that the cold irritates the lungs membranes which then triggers the asthma attack. The steroid strengthens the bodies defenses.
You have to decide which is the worse of two evils. Asthma attacks damage the lungs. That's a given. So is it better to have the attacks or risk the side affects of steroids?