Baby achne or rash ? Or something else...

Denise
FTM here looking for some answers. My little one has this "rash" on his face, behind his ears, and on his neck and a little bit on his head. I'm not sure if it's baby achne or an actual rash or maybe some kind of allergy ? All the products I use from the laundry detergent to his body wash/shampoo are fragrance free and for gentle skin etc...His skin is also very dry. Not sure if this is normal or what I could do about it, any helpful tips would be appreciated ! 😄