Michael L. Radzienda, MD SFHM
Most asthmatics, with the exception of runner asthmatics, are exposed to an environmental allergen which causes inflammation of the linings of the airways.
If the stimulus is removed, e.g.:removing a cat from your home after testing positive for cat dander on an antigen panel, one can seemingly make their asthma "go away". It is also true that younger atopic (allergic) individuals become less allergic with age, hence childhood asthma seemingly wanes with age for some individuals.
Lastly, there is always the misdiagnosis of asthma in lieu of other similar syndromes: ABPA, Occupational toxins , etc....