How do antihistamines & other antinflammatories taken longterm affect accuracy of esr,crp, ptt tests when r/o lupus or other ctd's?

Little or none: ESR (sed rate) and C-reactive protein are actually of little real use in the lupus workup, and the public and physicians set too much by them generally. PTT is used to look for the "lupus anticoagulants" that paradoxically cause thrombosis. The common meds that affect small molecules like histamine and prostaglandins don't impact production of the proteins involved in these tests, or lupus testing