Help! 4 month old possibly has eczema...

FTM...over the last two weeks i noticed a small rash and dry patches. His 4 month appt was right after a mini flare of about 2 days but was gone before the appt. I told the dr and he said it’s probably just from the weather changing and how dry it is. 4 ish days later it flares again. I keep moisturizing him and changed body wash to aveeno. Now the last 3 days it keeps getting worse. I started using eucerin eczema relief lotion. I already plan on calling the dr first thing this morning but anyone have any suggestions or similar situations with their babies? My heart hurts so much for my baby cause it looks so painful. He’s been more fussy but still laughs and smiles like normal.