French protocol for the diagnosis and management of giant cell arteritis.

Giant cell arteritis (GCA) is a large-vessel vasculitis that mainly affects women over fifty. GCA usually involves branches from the external carotid arteries, causing symptoms such as headaches, scalp tenderness, and jaw claudication. The most severe complication is ophthalmologic involvement, including acute anterior ischemic optic neuropathy and, less frequently, central retinal artery occlusion with a risk of permanent blindness. Approximately 40% of patients may have involvement of the aorta or its branches, which has a poor prognosis, although this is often asymptomatic at diagnosis. Diagnosis is largely based on imaging techniques such as FDG-PET combined with CT, CT angiography, or MRI angiography of the aorta and its branches. Polymyalgia rheumatica is associated with GCA in 30-50% of cases but may also occur independently. Treatment must be initiated urgently in the presence of ophthalmologic signs or when GCA is strongly suspected to prevent vision loss. The gold standard to confirm the diagnosis is temporal artery biopsy. However, Doppler ultrasound and vascular imaging are also reliable diagnostic techniques. Initially, high doses of corticosteroids like prednisone (40-80mg per day) are the mainstay of treatment. Tocilizumab can be discussed in combination with prednisone for corticosteroid sparing. Long-term management is essential, including monitoring for disease recurrence and corticosteroid-related side effects. General practitioners play a crucial role in early diagnosis, directing patients to specialized centres, and in managing ongoing treatment in collaboration with specialists. This collaboration is essential to address potential long-term complications such as cardiovascular events. They can occur five to ten years after the diagnosis of GCA even when the disease is no longer active, meaning that vigilant follow-up is required due to the patients' age and status.