title: The challenge and need of defining axial psoriatic arthritis.
authors: José Luis
authors: JL
authors: Fernández-Sueiro
mesh_terms: D015535:Arthritis, Psoriatic / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology*; D018450:Disease Progression; D006801:Humans; D007596:Joints / Q000473:pathology; D012720:Severity of Illness Index; D013131:Spine / Q000473:pathology