Atypical form of Giant cell arteritis (GCA), involving the absence of American College of Rheumatology (ACR) criteria, should be suspected before fever or inflammatory syndrome of unknown origin in the elderly. In that case, the diagnosis may be complex insofar as there are many possible infectious, inflammatory or tumorous etiologies. Completion of multiple and / or invasive clinical investigations can be questionable in a frail elderly population. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) is a non-invasive examination of high sensitivity and specificity in the diagnosis of GCA which may reveal abnormal fixation of the wall of the aorta and its branches. Its negative predictive value close to 90 % is also a strength to exclude the diagnosis. FDG-PET/CT is also effective in the search for differential diagnoses. On the other hand, FDG-PET/CT should not be prescribed in front of typical form of GCA in which ACR criteria are met. This clinical case illustrate the place of FDG-PET/CT in the diagnostic strategy of an inflammatory syndrome in an elderly patient for whom GCA is suspected.
Increased Metabolic Activity on 18F-Fluorodeoxyglucose Positron Emission Tomography–Computed Tomography in Human Immunodeficiency Virus–Associated Immune Reconstitution Inflammatory Syndrome
