S2473 A Case of Familial Mediterranean Fever Diagnosed by Abdominal CT Scan in a Patient Previously Diagnosed With Functional Abdominal Pain

Abstract

Introduction: Familial Mediterranean fever (FMF) is a hereditary autoimmune disease in which patients present with periodic, self-limited episodes of fever and serositis. It is prevalent in individuals of Middle Eastern origin. Since no definitive diagnostic test is available, FMF is suspected based on clinical symptoms; there are major and minor criteria to aid in making the diagnosis. Imaging modalities are not included in these criteria. We present a patient whose only symptom was recurrent abdominal with no family history of FMF. At the time he was diagnosed with Functional Abdominal Pain. FMF was suspected based on unexplained focal peritonitis on computerized tomography (CT). Case Description/Methods: A 45-year-old male of Middle Eastern descent was seen in clinic complaining of episodic right upper quadrant (RUQ) abdominal pain since he was 17 years old. The pain occurred once or twice per month. Over the years he had multiple visits to the emergency department and extensive work up including endoscopic evaluation and imaging studies. He underwent cholecystectomy, and bilateral inguinal hernia repair without benefit. He was diagnosed with Functional Abdominal Pain then. When evaluated in our clinic, lab work showed mild iron deficiency anemia; otherwise, unremarkable. Upper endoscopy, colonoscopy, small bowel series and capsule endoscopy were normal. 3 months later he presented to our ER with an acute episode of severe RUQ pain. He was afebrile; abdominal exam was remarkable for localized tenderness in the RUQ. Lab work was remarkable for an elevated erythrocyte sedimentation rate of 31. Abdominal CT was only remarkable for fat stranding around the hepatic flexure and the proximal half of the transverse colon. Colonoscopy was normal with no evidence for segmental colitis to explain the inflammatory changes. Given the history of recurrent abdominal pain, ethnicity, and focal unexplained peritonitis on CT scan, FMF was suspected, and treatment with colchicine was initiated without recurrence of symptoms for now several years since the diagnosis, meeting diagnostic criteria for FMF. Discussion: If not considered, FMF can remain misdiagnosed for many years leading to unnecessary procedures and surgeries. This was an unusual presentation with afebrile episodes of intermittent RUQ pain with the diagnosis ultimately suspected by CT imaging and confirmed by response to colchicine. Clinicians should consider FMF in patients of high-risk ethnic origin presenting with unexplained focal peritonitis on CT scan.