Concurrence of polyarteritis nodosa and multiple sclerosis

: Polyarteritis nodosa (PN) causes systemic vasculitis in the small to medium-sized arteries, which sometimes invades the central nervous system (CNS) (1). Multiple sclerosis (MS) is an immune-mediated demyelinating disorder of the CNS. A large prospective study revealed that first-degree relatives of MS patients are at increased risk of PN, but concurrence of PN and MS within an individual was not identified (2). Here, we report a case of PN with CNS lesions suggestive of MS.