Infantile acne or eczema?

Hi, 

My son is 8 months old, and for the last 2 months has been getting pimples on his cheeks. One particular one has been there 2 months now  It’s flat, but looks like a whitehead. His also started to get a red pimply rash around his mouth, which feels dry and quite rough. I’m wondering if this could be an intolerance to dairy, or if it’s quite common? I’ve tried using nothing at all, and I’ve tried Aveeno bath wash and moisturiser. Tonight I’ve used Oilatium cream to see if that will help. Does anyone have any advice or had a similar experience?