Justadrop, different people have sensitivities to PG, to VG, to certain flavors. I have friends who will get welts (red, itchy, bumps) and/or headaches and/or blurred vision from certain combinations. Some people switch to VG only, and organic flavorings. Others are PG-only, still others have to avoid cinnamon (or other things).
You could try some unflavored eliquid, a bottle each of PG-based and VG-based (a little distille dwater or high proof grain alcohol will thin out the VG), at whatever strength you use, see if one or both of them is okay for you. Get something that works, then branch out to try and see if it is one or several, certain flavoring(s) that cause trouble.
The medical side beats me, I'm not a doctor and even my wife (who is one) would say "go see your doctor". If it's minor enough, I'd work through it as described above.