Polyarteritis nodosa (PAN) is a necrotizing vasculitis of the medium-sized arteries. The symptoms and signs of PAN include purpuric skin lesions, mononeuritis multiplex, symptoms of mesenteric ischemia, and renal involvement. We report the first case of PAN manifesting as a neuropathy after influenza infection in Korea. A 68-year-old woman had fever, myalgia, hyperesthesia of both hand and foot, and lower extremity weakness. EMG findings showed severe sensorimotor polyneuropathy, such as multiple mononeuritis. A sural nerve biopsy showed vasculitis and Influenza A (H1N1) were positive. Our patient was treated by glucocorticoid and oral cyclophosphamide, thereafter, symptoms and signs improved. No recurrence has been observed for five months.

Keywords: Polyarteritis nodosa, Influenza infection, Neuropathy