P6300 - Polyarteritis Nodosa, a Rare Cause of Abdominal Pain

Philomena Burger, BA¹, Charlotte Blumrosen, MD¹, Alexandra France, MD¹, Danielle Marino, MD²
1University of Rochester Medical Center, Rochester, NY; 2University of Rochester, Rochester, NY

Introduction: Medium Vessel Vasculitides, including polyarteritis nodosa (PAN), are uncommon diagnoses that in atypical cases can present with abdominal pain as the only symptom. Mesenteric arteritis leads to vascular narrowing and resultant mesenteric ischemia, which can lead to bowel infarction and be life threatening if recognition is delayed. Early diagnosis with appropriate management is critical in improving patient outcomes. This case highlights the diagnosis and treatment of a patient with mesenteric ischemia due to PAN.

Case Description/

Methods: A 43-year-old male with type 1 diabetes mellitus presented with several weeks of postprandial epigastric and right upper quadrant pain, with associated weight loss of 20 lbs over the last 3 months. He had no nausea, vomiting, melena, hematochezia, NSAID use, alcohol or drug use. Initial vital signs were normal and physical exam was notable for diffuse abdominal tenderness with guarding. Contrasted abdominal CT showed near occlusive thrombosis of several branches of the superior mesenteric artery (SMA). Dedicated CT angiogram was obtained for further clarification and showed circumferential thickening of the SMA, inferior mesenteric artery and common hepatic artery with fat stranding and diffuse inflammatory changes concerning for vasculitis, but no occlusion. Gastroenterology was consulted to evaluate for other etiologies of abdominal pain and upper endoscopy was unremarkable. Rheumatology was consulted given suspicion for vasculitis and the patient underwent a PET/CT scan that showed FDG avid celiac, SMA, and proximal intrahepatic vessels, consistent with a diagnosis of PAN. He received IV methylprednisolone for three days and was started on cyclophosphamide for definitive management.

Discussion: Vasculitis, while rare, should be considered in the differential diagnosis in cases of abdominal pain without a clear etiology. In cases of vasculitis affecting the mesenteric vasculature, post-prandial abdominal pain occurs due to inflammation causing arterial narrowing and resultant ischemic injury. PAN is a vasculitis that is typically seen in males aged 30-60, with imaging showing circumferential wall thickening with stenosis of medium visceral vessels without occlusion/embolus. PET scan is usually required for definitive diagnosis.

Given the need for timely diagnosis and treatments to improve outcomes for patients with these rare vasculitides, gastroenterologists should remember to consider them when seeing patients with abdominal pain of unclear etiology.

Disclosures:
Philomena Burger indicated no relevant financial relationships.
Charlotte Blumrosen indicated no relevant financial relationships.
Alexandra France indicated no relevant financial relationships.
Danielle Marino indicated no relevant financial relationships.

Philomena Burger, BA¹, Charlotte Blumrosen, MD¹, Alexandra France, MD¹, Danielle Marino, MD². P6300 - Polyarteritis Nodosa, a Rare Cause of Abdominal Pain, ACG 2025 Annual Scientific Meeting Abstracts. Phoenix, AZ: American College of Gastroenterology.