This is a curious topic for me. Thank you for posting it!
I have read about allergic reactions, or sensitivities, to the ingredients to some juices. Where ever you are getting your juice from, ask about the specific ingredients used in the flavoring as that could be the problem.
I have also read that some people have sensitivities to VG and PG or outright allergic reactions to them. Both are main ingredients in the juices.
Now, don't take me for a pro here, I am only going by what I have read around here on the forum. I am trying to get as much information as I can about "The Vaping Experience".
I have only been vaping for about two months now. So far no sensitivities, except when the juice comes in contact with my face. I break out in a rash.
(okay, how that happened was: I had it on my fingers, and an itch occurred -naturally- on my cheek, and I itched it!). It only took less than a minute for the burning and the burning rash was there for a few days. I treated it like an abrasion; immediately cleansed it, and kept it clean.
The wheezing thing, I am curious about though... Did you smoke regular or "analog" cigarettes for a long time before vaping? I smoked for 41 years, I was diagnosed with oncoming COPD 6 months ago. I am not experiencing wheezing, but I am really only down to like two "analog" cigarettes a day now, I am trying to make the next day (I say it every day) a vape day only... All I can do is go one day at a time. Hey, I am not smoking 1 - 2 packs a day any more!
I am curious about the caramel and other flavors that are based on "food items" made from milk products, if they have some milk products in them. There are many "hidden" forms of dairy that many are not aware of (I have a sister who is DEATHLY allergic to milk products, so I am well aware of them). So if someone has a dairy sensitivity, the dulce du leche (which is caramel, basically) may make you have a reaction of some sort... and since you are ingesting it through vaping, wheezing may be the reaction your body is exerting as a warning to you about it. THIS IS ONLY AN OBSERVATION OF PROBABILITY BASED ON WHAT I KNOW ABOUT ALLERGIC REACTIONS FROM DAIRY... DO NOT PANIC... DO NOT TAKE THIS AS A DIAGNOSIS. PLEASE. I want to know, too. --Besides, I am an artist, not a med professional.