Unilateral Renal Artery Vasculitis: A Case Report.

Renal artery inflammation is typically observed as part of systemic vasculitis rather than as an isolated condition. Large vessel vasculitides, such as Takayasu arteritis and giant cell arteritis, as well as polyarteritis nodosa, may involve multiple vessels, including the renal artery. Isolated vasculitis of the renal artery is exceedingly rare with only eight cases reported worldwide. We describe a case of a previously healthy 53-year-old man who presented with a history of right flank pain which was attributed to renal artery vasculitis. Extensive radiologic studies revealed no evidence of inflammation in other vessels and laboratory evaluation for an underlying infectious, neoplastic or autoimmune cause was negative. Treatment with methylprednisolone, followed by azathioprine as a steroid-sparing agent, led to complete remission of the condition.