There are a lot of things that can trigger VCD--respiratory infections, odors, singing, emotional upset, post-nasal drips, allergies, and exercise. Who knows what triggers mine. It might be the allergies. It might just be some added stress in life, though most of the times I've had problems, I have not been stressed at all. We may never know for sure what my triggers are.
To try to treat it, I will first try to control it on my own. To do that I can practice lamas breathing and relaxation tricks to try to get my throat muscles to relax and start working correctly again. If that doesn't work and I still have attacks, I may have to go to speech/breathing therapy to teach my muscles in my neck, throat, chest, and abdomen to work like they are supposed to.
The hard part will be that I have no idea what triggers it for sure, so can't do things to try to prevent an attack. And once I do have an attack, there's no magic medicine to stop it--no medicine that helps at all actually. The good part is that its not just allergy attacks getting worse and worse! I won't have to cut all cat-owners out of my life! ;) And with practice, it can even go away completely someday. I'm praying that it does soon.