**Abstract**

Giant cell arteritis (GCA) is the most common vasculitis in adults, with the incidence increasing with the advancing age. The aorta and its branches, especially the carotid extracranial branches, are the classic targets of inflammation in GCA. Visual loss, upper limb ischemia, and stroke are complications described. Suspicion of GCA is a medical emergency, and patients need to be quickly diagnosed/treated to prevent irreversible damage. Headache is the most common symptom, and a new-onset headache in older adults should always raise the suspicion of GCA. Patients may also present with scalp tenderness or tongue/jaw pain. GCA is often found to be the cause of an obscure-origin fever in older patients. A positive temporal artery biopsy is considered the gold standard for the diagnosis, but imaging techniques enable the assessment of cranial and extracranial arteries and the aorta. Ultrasound of temporal arteries is recommended and noncompressible "halo" sign is the typical finding. PET, MRI, or CT may be useful for the detection of the disease in the aorta and other vessels. The treatment must be started promptly with prednisone 1 mg/kg/day. When visual symptoms/unilateral visual loss is present, methylprednisolone pulse is recommended. Methotrexate, leflunomide and tocilizumab may be effective and well-tolerated glucocorticoid-sparing agents in GCA. Cardiovascular diseases are the leading causes of death in patients.

**Keywords:** giant cell arteritis, T17, IL-6, pathogenesis, treatment, tocilizumab
