In a patient with recurrent episodes of GCA that flare shortly after steroid tapering, how do you differentiate between steroid-dependent inflammatory relapse, an alternative autoimmune vasculitic process, and a paraneoplastic phenomenon?

Paraneoplastic disease rarely behaves like GCA with ischemic manifestations. If a non-GCA vasculitis is suspected, perhaps repeat biopsy or serologic testing for other markers could be done. I'm not sure of the value of these tests, however, given that the treatment approach with immunosuppression w...