Relapses in giant cell arteritis: Updated review for clinical practice

Giant cell arteritis (GCA), the most common primary vasculitis in adults, is a granulomatous systemic vasculitis usually affecting the aorta and its major branches, particularly the carotid and vertebral arteries. Although remission can be achieved in most patients with GCA using high-dose glucocorticoids (GC), relapses are frequent, occurring in >40% of GC-only treated patients, mostly during the first two years after diagnosis. Relapsing courses lead to high GC exposure, increasing the risk of treatment-related adverse effects. Although tocilizumab is an efficacious GC-sparing therapy that allows increased sustained remission and reduced cumulative GC doses, relapses are common after drug discontinuation. This narrative review examines the most relevant features of relapses in GCA, including its definition, classification, frequency, clinical, laboratory, and imaging characteristics, chronology, probable pathophysiology, and predictive factors. In addition, we discuss treatment options for relapsing patients and the effect of relapses on patient outcomes.