Chronic Itchy body rash in child

I'm wondering if anyone or anyone's child had this as a symptom?
Chronic body rash- raised bumps that itch.
I'm trying to find out what is causing my sons bumps... Possible gluten. Possible reaction to antibiotics via breast milk or possible Lyme ... Chemicals etc. doctors seem to want to just call it excema if they can't find a cause.

I've read that RMSF rash can be itchy in some children - is it possible that he has these infections?

If you are seeing a LLMD/LLND, what about taking him to your next appt if one is coming up soon - or just calling them and explaining what's going on and see if they will see him just to rule out tick-borne infections?