Capsule endoscopic features in a severe case of eosinophilic enteritis: A case report.

BACKGROUND Eosinophilic enteritis (EoN) is a rare digestive disorder characterised by eosinophilic infiltration of the small intestine. Diagnosis relies on the recognition of characteristic endoscopic findings and the identification of eosinophilia in gastrointestinal tissues. Capsule endoscopy is particularly useful for detecting lesions in the small intestine, a region that is difficult to assess. However, the endoscopic features of EoN are poorly understood.

CASE PRESENTATION A 20-year-old Asian man presented with a one-month history of right lower quadrant abdominal pain accompanied by nausea, vomiting, and diarrhea occurring 1-2 times per day. Laboratory tests revealed peripheral blood eosinophilia (665/μL; normal range, 20-400) and elevated C-reactive protein level (28.8 mg/L; normal range, <10 mg/L). Abdominal computed tomography revealed uneven thickening of the ileum and the ileocaecal region. Capsule endoscopy (MC 2000; Intromedic, South Korea) revealed multiple areas of erythema, villous atrophy, erosion, ulceration, and oedema throughout the small intestine. Histopathological examination of a biopsy sample confirmed mucosal infiltration of more than 50 eosinophils per high-power field, leading to the diagnosis of EoN. The patient was administered intravenous methylprednisolone at 40 mg/day, which resulted in significant symptom relief within two weeks. The dose was gradually tapered to 15 mg/day. Follow-up capsule endoscopy performed two months later showed complete resolution of the mucosal lesions in the small intestine.

CONCLUSION This case highlights the key capsule endoscopy findings in EoN, including multiple areas of erythema, villous atrophy, erosion, ulceration, and oedema throughout the small intestine, which may serve as a diagnostic guide for cases in which small bowel biopsy is not feasible.