I also have EIA. I was diagnosed after an attack at a water park while on my honeymoon. I was away from cycling for about 20 years, but when I returned last winter, so did my EIA. After speaking with my doctor, and experimenting with a couple of methods, we've found the following works for me.

About 30 - 60 minutes before a ride, I take 2 Primatene tablets. If the ride is going to be more than 3 hours, then I continue taking the tablets during the ride (every 3.5 - 4 hours apart). I also bring a rescue inhaler with me on the ride. The Primatene tablets (at least for me) are a very good preventative measure, but I have to remember to take them, and take them BEFORE I start the ride.