Possible PG allergy? Does anyone have any knowledge or experience with this?

I don't know 100% if I am experiencing a PG allergy, but I'm just trying to see if I can get any solid theories here.

I typically vape 100% VG and have no problems. A few days ago, a coworker gave me a few 50/50 PG/VG juices she didn't care for. I have noticed that in the past few days, I've started breaking out on my chest (which is a big deal, as my chest has been flawless my entire life until now) and when I do vape, my throat feels tight for a few seconds (but I can't tell if this is just the 'throat kick' that PG gets or if this is a big deal).

Has anyone here ever had a confirmed PG allergy? Or does anyone have any good guesses to what is happening? Again, these issues I'm having may be entirely unrelated to vaping but I'm trying to shoot down all the possibilities I can.