I just thought about why I sometimes do it when i'm in my default mode and came to the conclusion that it may be just like t. gondii.
I mean it makes sense. By popping the pimples you may weaken your immune system which makes it easier for the parasite not to be cared about.
So I did a quick literature research and found... nothing. Not even about anything somehow related to reasons for why we pop pimples... Someone interested or knowing more?