Mimickers of Large Vessel Giant Cell Arteritis.

Giant cell arteritis (GCA) is a large-vessel granulomatous vasculitis occurring in patients over 50-year-old. Diagnosis can be challenging because there is no specific biological test or other diagnoses to consider. Two main phenotypes of GCA are distinguished and can be associated. First, cranial GCA, whose diagnosis is usually confirmed by the evidence of a non-necrotizing granulomatous panarteritis on temporal artery biopsy. Second, large-vessel GCA, whose related symptoms are less specific (fever, asthenia, and weight loss) and for which other diagnoses must be implemented if there is neither cephalic GCA nor associated polymyalgia rheumatica (PMR) features chronic infection (tuberculosis, Coxiella burnetti), IgG4-related disease, Erdheim Chester disease, and other primary vasculitis (Behçet disease, relapsing polychondritis, or VEXAS syndrome). Herein, we propose a review of the main differential diagnoses to be considered regarding large vessel vasculitis.