A case study of polyarteritis nodosa initially suspected as small vessel vasculitis

Polyarteritis nodosa (PAN) is a rare systemic vasculitis characterized by segmental necrotizing inflammation of medium-sized arteries. This presents a case of a 48-year-old female with a one-month history of severe pain and burning sensation in her right hand, initially suggestive of small vessel vasculitis. Despite normal inflammatory markers, imaging studies revealed characteristic findings of PAN, including diffuse arterial narrowing, focal ectasia, and microaneurysms in multiple vascular beds. Pulse methylprednisolone therapy resulted in significant clinical improvement, followed by intravenous cyclophosphamide to suppress the autoimmune response, with subsequent disappearance of the microaneurysms. This case highlights the diagnostic challenges and importance of a multidisciplinary approach in the management of PAN, emphasizing early recognition and intervention to prevent complications.