Is this infant acne? What can I do to make it go away?

hmm.. looks like it could be heat rash. Looks like the first type that is mentioned in this article: http://www.healthline.com/health/heat-rash-pictures-remedies#Overview1 Keeping baby cool and dry is the simplest way to combat this. If it is baby acne, you can try using breast milk to help clear it. Just apply a few drops to the spots would do.