Baby acne or rash?

Steph92

My 4.5 week old baby has these bumps all over his face, mostly on his forehead and chin. Trying to figure out if it’s baby acne or a rash? ive been washing his face with mild baby soap and trying to keep it clean from spit up/ milk and putting baby lotion on 3x a day. We started introducing formula 2 weeks ago if that makes any difference ? thank you!