Baby eczema or baby acne

Does anyone know which one it is? My son is 5 weeks old. Last Friday, he had a dr’s appt for his hepatitis shot and we asked the doctor about his skin and she said it was baby acne. We tried baby aveeno eczema therapy (the dr recommended this) on Saturday and it didn’t work. It seemed like it got worse. I noticed also it gets worse when he is fussy or hot then kind of calms down but still there.