First of all, taking Tumeric isn’t going to mask an inflammatory markers, as Tumeric really isn’t all that effective to begin with. The key distinguishing features that differentiate PsA from RA are 1.) No RA factor present in labs, regardless of presence of HLB-B27; 2.) Assymetric presentation of symptoms - PsA tends Not to effect both sides of the body equally, one side of the body will have affected joints, whereas the other side may not; 3.) PsA tends to affect the distal joints of the fingers (the very end joints), whereas with RA it is the middle joints; 4.) With PsA there is usually (but not always) skin involvement, psoriatic lesions.
Many, if not most, of us with PsA have normal labs as regards inflammatory markers, though they might be elevated during a particularly bad flare. I, for one, have never had a lab where my Sed Rate or C-RP was elevated outside if the normal range. Whether or not you are diagnosed with PsA or RA, likely the treatment will be the same, as they are both immune system diseases requiring the administration of anti-rheumatic drugs.