S4018 Corticosteroid-Dependent Eosinophilic Colitis: A Rare Case Report

Introduction: Eosinophilic gastrointestinal disorders (EGIDs) are rare occurrences in adults, with eosinophilic colitis (EC) being the least common form. EC is defined by dense eosinophilic infiltration of the colon in the absence of identifiable secondary causes. Diagnosis is often delayed due to nonspecific symptoms and the need to exclude mimickers such as infections, inflammatory bowel disease (IBD), and food allergies, making it a diagnosis of exclusion. Here, we present a case of a 64-year-old man with EC dependent on corticosteroid therapy. Case Description/Methods: A 64-year-old man presented with chronic diarrhea, unintentional weight loss, and abdominal pain of 2 years of evolution. Laboratory results were remarkable increase total IgE >1,000. He underwent colonoscopy with biopsy which revealed normal colonic mucosa. Histology was positive for eosinophilic infiltration (>100 cells) at sigmoid colon. He was started on prednisone 40 mg daily and symptoms improved however upon tapering it recurred. Subsequently, azathioprine 100 mg daily was added and a lower dose of prednisone was started but the patient failed to improve. Due to dependence on corticosteroid, anti-TNF therapy is considered as corticosteroid sparing therapy in this patient. Discussion: Eosinophilic colitis remains a rare form of eosinophilic gastrointestinal disorder and can present with nonspecific symptoms that mimic other gastrointestinal conditions, such as IBD. In this case, a 64-year-old man experienced chronic diarrhea, weight loss, and abdominal pain. Diagnostic criteria have not been standardized, but a diagnosis can be made based on symptoms, endoscopic findings, and histopathological examinations of biopsy. The patient’s EC was confirmed by histological findings revealing eosinophilic infiltration, despite having normal colonoscopy findings. The patient responded well to prednisone but relapsed upon dose reduction and showed no improvement with azathioprine. This case highlights the challenge of diagnosing and managing refractory EC due to possible steroid dependence. Although little data are available, anti-TNF agents remain possible therapeutic options and were considered here. This case highlights the importance of biopsy in diagnosing EC and suggests a possible viable use of biologic agents in managing steroid-dependent EC.