Eosinophilic Duodenitis and Jejunitis with Ascites and Peripheral Eosinophilia: A Diagnostic Challenge—Case Report

Background: Eosinophilic jejuno-duodenitis is a rare inflammatory disorder characterized by eosinophilic infiltration of the gastrointestinal tract, with highly variable clinical presentations. Mucosal eosinophilic duodenitis and jejunitis associated with ascites is uncommon and may mimic inflammatory or neoplastic conditions. Case Presentation: A 26-year-old male presented with persistent left-sided abdominal pain without bowel habit changes. Laboratory investigations revealed only slight inflammatory syndrome and peripheral eosinophilia. Contrast-enhanced abdominopelvic computed tomography demonstrated minimal ascites and circumferential wall thickening with contrast enhancement of duodenal and jejunal loops in the left flank. Given the nonspecific imaging findings, differential diagnoses included Crohn’s disease, intestinal lymphoma, and infectious enteritis. Endoscopic evaluation with histopathological analysis confirmed dense eosinophilic infiltration of the duodenal and jejunal mucosa, establishing the diagnosis of eosinophilic jejuno-duodenitis after exclusion of secondary causes. Management and Outcome: The patient was treated with budesonide, with rapid clinical improvement and resolution of inflammatory markers. Follow-up magnetic resonance enterography performed three months after initiation of treatment demonstrated complete resolution of bowel wall thickening and disappearance of the minimal ascites. Conclusions: Eosinophilic jejuno-duodenitis should be considered in young patients presenting with small bowel thickening, ascites, and peripheral eosinophilia. Awareness of this entity is essential to avoid misdiagnosis and unnecessary invasive procedures.