Toddler Rash

[gingermum1992]

My LB developed a rash on his back that looks like little acne spots - took him to the doctor and they said it was excema and recommended epiderm cream. It didn't get any better so took him back and they gave him antibiotics and said it was a skin infection. Finished those and it came back to called again and they've just said it's a contact reaction so no soap, fragranced washing powder etc - but it's still there and has now spread to his belly and sides - he's completely fine in himself, no temp, sleeping fine and done the glass test and it blanches

Anyone have any ideas of what it could be?
My next thought was maybe something dietary?

Could it be pityriasis rosea?

I thought that (after Googling baby rashes) but He didn't have a "Herald patch" but I think that's what the GP thought when he had the antibiotics

It doesn't seem to bother him at all (not even itching) but I'm at a loss to what it could be!

From what I remember antibiotics aren’t commonly used for it. I wonder if the GP thought it was a strep infection perhaps.

When my son had it, it was around for months and then just disappeared from one day to the next, and never bothered him at all.