einsteinsghost
I have found that I get pimples in/on places like my ears/cheeks/chin/etc when they are in contact with unclean things: whenever I use a strange phone, for example, 99% of the time I will get a nasty pimple on or near my ear and often on my chin, if the phone touched. If I don't change my pillowcase every few days, I will get them on the side I sleep on. I was a nursing aide for awhile, and if I used someone else's stethescope, I would always get pimples inside my ears. You get the idea. Anyhow, so every once in awhile, I will take a bottle of rubbing alcohol or some other kind of disinfectant and swab down everything that could come in contact with my skin (including my own telephone). My skin is far from perfect, but it helps a *lot* to keep everything as clean as possible.
Good luck, though. I hope you don't have this problem again.