A Rare Presentation of Polyarteritis Nodosa.

Polyarteritis nodosa (PAN) is a rare form of necrotizing medium-vessel vasculitis. PAN has the potential for widespread organ involvement, but the skin, renal, neurologic, and musculoskeletal systems are most commonly involved. A definitive diagnosis can be made with a biopsy of an easily accessible organ such as the skin or an involved nerve or muscle. We present a case of a 66-year-old female with no significant past medical history who presented with chest and epigastric pain. She was subsequently found to have computed tomography angiography (CTA) findings consistent with PAN, including areas of arterial narrowing alternating with areas of aneurysmal dilation confined to the mesenteric arteries. A biopsy of the involved arteries was deemed unsafe and ultimately not performed. Her lab findings were remarkable for elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) and unremarkable for a broad infectious disease workup. Suspicion of PAN was further strengthened by a positive response to, and eventual full recovery on, high-dose steroids alone.