Polyarteritis nodosa associated with essential mixed cryglobulinemia revealed by subarachnoid hemorrhage.

Polyarteritis nodosa (PAN) is a systemic necrotizing vasculitis mediated by intravascular deposition of immune complexes. We report a 55-year-old man with PAN revealed by CNS vasculitis with subarachnoid hemorrhage and brainstem vasogenic oedema, associated with essential mixed cryoglobulinemia. In spite of aggressive treatment (steroids and cyclophosphamide), the patient became tetraplegic. A pathophysiological relationship between cryoglobulin and PAN can be suspected. Mixed cryoglobulinemia may trigger vasculitis with PAN features, possibly explaining the lack of treatment response.