I also have developed for want of a better term allergic asthma, and react very badly to certain types of cigarette smoke, some air fresheners/ perfumes and feathers. I can go weeks or even months without even thinking about it and then something will trigger an attack and I'll be very vulnerable to a repeat attack for a while. One thing that appears to help me recover quicker when I've had an attack, and boost my resistance to another one is inhaling steam, especially if it has something like Vick's vapour rub or Bengue's balsam in it. Both have ingredients like menthol and eucalyptus in them. I also find that stress increases the likelihood and severity of attacks.