Oh I know what I can add
Resistive breathing techniques!
During the onset of an asthma attack (be it exercise or particle) you can purse your lips and provide pressure for your exhale.
I'm not sure what it does but the effect is pretty immediate. Somewhere after 2 minutes to 5 minutes breathing should become easier.
Also breath in through the nose exhale out the mouth and keep it slow and steady.
I also learned to do the same thing. What it does, I think, helps calm things down and makes the handling of this better--to the point that perhaps dependence upon an inhaler could be minimized.
Many people I know, when an attack comes on, would progress into panic and that just makes things worse.
- Ceicei