Successful Treatment of Steroid-resistant Eosinophilic Gastrointestinal Disease with Mepolizumab

We experienced a case of treatment-resistant eosinophilic gastrointestinal disease (EGID). The patient, a 46-year-old man, presented with a fever, persistent abdominal pain, and an elevated peripheral eosinophil count. Eosinophil infiltration of the intestinal mucosa was also observed, and EGID was diagnosed. Corti-costeroid therapy was initiated, but no improvement was seen. However, after mepolizumab (anti-interleukin 5 antibody) was administered, the patient's disease was controlled. Currently, the indications for mepolizu-mab are limited to bronchial asthma and paraneoplastic eosinophilic polyangiitis, but the experience herein reported suggests its usefulness in the treatment of EGID.