That sucks, trust me I'd know. I don't know if this is the issue, but maybe you should try sleeping on your back and not let your face touch your pillow. Because the oils from your skin and hair get absorbed into the pillow, it could cause breakouts if your face comes in contact with the pillow. Anyway, don't worry too much. It's just acne :) everyone gets it.

Sounds as if you need to wash your pillow cases.

its most likely a nerve problem because i have the same thing, my left cheek grows hair alot faster than everywhere else

Wash yo pillowcases. Twice a week if need be.

Have you considered wearing the mask from Phantom of the Opera?

The best way to prevent this is to wash your pillow case at least twice a week

wash your pillow case. takes the oil out.

Satin pillowcases, my friend!

At least it's only one side........

Though washing your sheets is a good idea, if you'd recently done just that, you could possibly be having a reaction to the detergent (or scent booster, fabric softener, etc). Speaking from experience here. My family now uses "ALL free and clear", so no more Jekyll & Hydes at this house!