Primary Eosinophilic Colitis Manifesting As Acute Appendicitis: A Case Report and Literature Review.

Eosinophilic colitis (EC) is a rare inflammatory disorder characterised by eosinophilic infiltration of the gastrointestinal tract, often resulting in varied clinical presentations. The role of the appendix in such inflammatory processes remains underexplored. We describe the case of a 48-year-old male who presented with acute abdominal pain, initially managed as uncomplicated appendicitis. He had a history of chronic diarrhoea and no atopic background. Histological examination of the resected appendix revealed eosinophilic infiltration without evidence of acute inflammation. Subsequent investigations ruled out secondary causes, leading to a diagnosis of primary EC. This case highlights the potential for eosinophilic appendicitis to mimic acute appendicitis clinically and the need for postoperative evaluation to exclude systemic eosinophilic gastrointestinal disorders. This represents, to our knowledge, a case of primary EC resolving after appendicectomy. We hypothesise that the appendix played a contributory role in the maintenance of chronic mucosal inflammation in this patient.