Anyone know what this rash is? Eczema? Ringworm? Help! Please read.

My son got eczema about a month ago but it had been getting better with lots of good lotion. Then about a week ago he got this red circular rash on his chest. I messaged a pic of it to his pediatrician and she said probably still eczema but possibly ringworm. She said to apply lotion 2x a day and if it gets worse it’s probably ringworm and to start applying over the counter ringworm cream 2x a day. It got worse so we started with the ringworm cream but it keeps getting worse!

We have an appt with the dr on Thursday and when I messaged her a week ago she had said it was ok to wait until then, but I just messaged her again with another pic since it’s gotten a lot

worse.

He is 4 months old and just starting to teethe. Exclusively breastfed. We haven’t used any new detergents or lotions or soap or anything like that. He doesn’t scratch at his body but he also has the rash on his head and he’s been trying to scratch his head a lot the past couple of days. Any ideas mamas?