How long vaping?
SOOOO many people report skin issues, like pimples, as part of quitting cigarettes, that it's definitely part of the process of your body getting off all the OTHER addictive chemicals (other than nicotine) that cigs contain.
Not saying don't check it out - it COULD be allergic issue with PG or VG in the liquid.
But there's even a term for - Quit Zits...
You could check with a doctor or dermatologist, and if you suspect the liquid, could experiment with different blends.
Hope you get it solved!!