Rash all over 4 month old … ftm

Hello! My baby will be 4 months in three days… his rash started with a spot here and there on his chest and thigh but now it’s all over. Originally his dr said it was eczema from photos we sent her, so she had us start using eczema cream. But it’s just been spreading. Has anyone’s baby had this before? Or does it look familiar to anyone? …waiting for his dr to call me back, but I’m sure you all understand how long waiting feels and how horrible it is! Any and all advice/comments are appreciated… thank you ! (Also, I have eczema as well but I’ve never heard of it being contagious?)