Without Headache: Fever of Unknown Cause Due to Giant Cell Arteritis
Giant cell arteritis is a chronic granulomatous vasculitis of unknown etiology and occurs generally in patients older than 50 years. Fever can be the only sign, although its clinical manifestations usually include typical symptoms, such as headache, scalp tenderness, visual disturbances, jaw claudication, or the association with polymyalgia rheumatica.1 In a retrospective cohort of GCA patients, 15 of 100 patients had fever of unknown origin as initial manifestation of the disease.2 The involvement of large vessels in GCA is common and may lead to severe complications, such as aortic aneurysm or dissection.3 On the other hand, owing to sneaky clinical presentation and possible lack of typical symptoms of cranial GCA, it can be underrecognized and have diagnostic delay.3,4
Giant cell arteritis should be taken into account in the differential diagnosis of fever of unknown origin in elderly people, and an increased awareness of large-vessel involvement in GCA is required. 18F-FDG positron emission tomography may be a useful and very sensitive tool in such diagnostic workup by early detecting vessel wall inflammation and visualizing all the potentially involved large vessels.