I second the pp. it will clear up on its own

It clears up on its own. Best thing to do is just leave it alone. 3-4 weeks old is when it shows up but not to worry, it will go away.

You can put breast milk on it but what really worked for us was hydrocortisone cream. Our pediatrician prescribed a super strength cream and within a couple weeks his acne went away.

Breastmilk

I would just use a mild soap on it