A case of polyarteritis nodosa associated with cytomegalovirus infection.

A 77-year-old man suffering from prolonged fever of unknown origin and bilateral leg edema was referred to our hospital. On physical examination, he had fever, general fatigue, bilateral lower leg edema, and muscle weakness of the right upper extremity and left lower extremity. Neurological examination indicated motor and sensory disturbance. Electromyography revealed mononeuritis multiplex and myopathy. A biopsy of the left biceps muscle indicated necrotizing vasculitis with fibrinoid necrosis. Considering all the data together, he was diagnosed as having polyarteritis nodosa (PAN) and concurrent active cytomegalovirus (CMV) infection. His symptoms improved promptly on treatment with 50 mg of prednisolone. This case emphasizes the importance of CMV infection as one of possible etiologies of PAN and reports a therapeutic strategy for this syndrome.