Giant cell arteritis with normal inflammatory markers: case report and review of the literature.

Giant cell arteritis (GCA) is a granulomatous vasculitis involving large- and middle-sized arteries, with a predilection for cranial arteries. In this paper, we aim to describe a case of a biopsy- and ultrasound-proven GCA, presenting with anterior ischemic optic neuropathy (AION) and normal CRP and ESR at diagnosis and during follow-up, and to review the literature on GCA cases with low inflammatory markers, with a particular focus on the presence of eye involvement. Both CRP and ESR are important in the diagnosis of GCA; occurrence of this disease with normal acute phase reactants is unusual but does not rule out the diagnosis. Headache and visual manifestations were the most common symptoms reported in these cases; therefore, patients with the clinical suspicion of GCA require immediate ultrasound and/or temporal artery biopsy for correct diagnosis and treatment initiation in order to avoid permanent visual loss.