Originally Posted by RiPHRaPH
*** FEWER than 10% of all people actually have true EIA, even if they have symptoms during exercise. Most people just have UNDERdiagnosed chronic asthma that is exaccerbated with exercise.
Asthma is an inflammation of the airways, causing a narrowing and ultimately a spasm in severe instances.
EIA does not involve this inflammation. It is caused by decreased water flow and other psychologic changes.
Has the exact mechanism of EIA ever been clearly pinned down? What I've read is that the evaporative loss due to increased ventilation of dry and/or cold air causes increased osmolality in mucosal cells. This increased osmolality is supposed to cause bronchial smooth muscle contraction (spasm), but also activates mast cells to trigger the vasodilation and inflammatory cascade you see with normal asthma.