Newborn rash

Rebecca

Hi all, in need of some advice. My 8 week old has got this rash on his face and neck. It’s newly appeared and does not seem to be bothering him but I’m not sure what it is or what is causing it. He’s been eating more the last day (and so waking up more often for feeds) but aside from that is happy, smiling and no temperature. Any advice would be great!