Hello everyone. Girls, could you tell me, our baby's head has been covered…

Hello everyone. Girls, could you tell me, our baby's head has been covered in pimples for a month now, they're really strong. The doctor says it's just a simple acne and we don't need to do anything, it will probably go away on its own. There are also small pimples on the face and some have started on the body, but not like on the head. What could this actually be?