Hi, My 5 Week Old Baby Has A Recurring Rash

Hi, my 5 week old baby has a recurring rash that started on his face and spread to ears , chest , back and arms. It goes and comes and looks like clusters of really tiny red bumps. For the last week the texture of it has changed and the Bumps are more flat and interconnected plus there are many tiny black dots in the middle of many of the bumps... it almost looks like he has an outbreak of blackheads...
The black spots are only on the face though. Wgat could this be? He doesn't scratch his face so it doesn't seem to be itching