baby acne

how long does baby acne usually last? is this normal? some days it's mild, some days it's bad (like now). it's nowhere else but his face and head with red areas on the side of his head. it's been a couple weeks and I was thinking it should have healed/gone away by now. he gets little yellow patches on his eyebrows too like burst pimples. I've been wiping his face off with a wet cloth once a day, should I be doing anything else? he's seven weeks old.