Polyartheritis Nodosa Presenting as Fever of Unknown Origin: Report of a Rare Case

ABS TRACT Classical polyartheritis nodosa (PAN) is a systemic vasculitis which affects small and medium sized arteries, and characterized by necrotizing inflammatory lesions. The disease may also manifest as fever of unknown origin. In this case, a 44-year-old male patient who was followed up due to high fever, and diagnosed with PAN according to the American College of Rheumatology (ACR) 1990 criteria after exclusion of all infectious causes which could be tested was presented. The patient achieved remission with high-dose prednisolone, and monthly pulse cyclophosphamide treatment. Systemic vasculitis syndromes should be definitely considered in the etiology of fever of unknown origin, though they are seen rarely.