[A Rare Differential Diagnosis of Chronic Cough].

 We report on a 62-year-old male patient with dry cough for 3 months, constitutional symptoms and elevated inflammatory markers.  Despite extensive diagnostics no infectious, malignant or rheumatologic disease could be found. Bronchoscopy with bronchoalveolar lavage showed lymphocytosis. 18-FDG-PET/CT demonstrated increased metabolic activity of the aorta and its primary branches.  We diagnosed large vessel vasculitis consistent to a subtype of giant cell arteritis (GCA) without cranial manifestation. Immunosuppressive therapy resulted in prompt resolution of symptoms and normalizing of inflammatory markers.  Elderly patients with unexplained fever, cough and constitutional symptoms should be investigated for GCA, even when classic symptoms are absent. Respiratory symptoms occur in about 4 % as initial and only presenting manifestation of GCA and in about 9 % along with classical symptoms.In cases with unclear focus of inflammation 18-FDG-PET/CT is becoming more and more important as a diagnostic tool.