Dust and cold water is the cause of asthama and the best way is to be as far as u can from dust.

It depends if you want quick relief or a solid cure which takes much longer by building an immunity.

Your choices are to control your environment (keep a clean house, have hardwood floors and sweep instead of rugs and vacuuming, use hypoallergenic products, avoid foods you are allergic to, etc.) and, if that is not enough, medications (antihistamines, Singulair, etc., which you may be able to take in combination).