Successful Treatment of Eosinophilic Gastroenteritis with Clarithromycin
A 52-year-old man was admitted to the hospital with abdominal pain, abdominal distension, and diarrhea. He had no history of food allergies or bronchial asthma. Clinical examination was unremarkable with the exception of lower abdominal tenderness. A complete blood count revealed a white blood cell count of 13,990/mm3 with an eosinophil count of 8,674/mm3 (62.0%). The serum immunoglobulin E level was 2,400 U/mL (normal, 6 to 90) and a radioallergosorbent test was positive for numerous allergens, including common foods. The serum level of C-reactive protein was 1.23 mg/L, and those of antinuclear antibody and anti-neutrophil cytoplasmic antibody were normal. Computed tomography (CT) of the abdomen revealed thickening of the small intestinal walls and ascites (). Endoscopic examination showed thickened and erythematous antral, duodenal, and ileal folds (). Biopsies of the ileum and rectum showed eosinophilic infiltration (). Ascitic fluid revealed an abundance of mature eosinophils against a bloody background. No malignant cells or microorganisms were identified. The final diagnosis was EGE.\nThe clinical course of the disease is shown in . The patient was treated with prednisolone (PSL) at 40 mg/day for 2 weeks which led to a rapid improvement in the symptoms and the eosinophil counts (0/mm3). PSL was then tapered to 20 mg/day and the patient was discharged from hospital. After discharge, the PSL dose continued to be tapered uneventfully until the dose reached 3 mg/day, at which point the abdominal pain recurred and there was a rapid increase in the peripheral eosinophil counts (9,772/mm3; first relapse). The PSL dose was therefore increased to 20 mg/day, which caused a rapid improvement of eosinophilic counts (99/mm3). However, when PSL was tapered again to a maintenance dose of 5 mg/day, eosinophil counts began to increase without symptoms (second relapse). Because serum glucose levels rose to more than 200 mg/L during the PSL treatment at a dose of 10 mg/day, it was determined that the dose could only be increased to 6 mg/day. However, eosinophil counts continued to increase (351/mm3), so CAM at 400 mg/day was added after obtaining informed consent and this led to a gradual improvement of eosinophil counts (132/mm3) after 2 weeks. The intention at that point was to taper the PSL dose to 5 mg/day, but the patient was asymptomatic and therefore did not take PSL for 3 weeks because of the potential for hyperglycemia. Eosinophil counts began to increase again (521/mm3; third relapse). Although the patient was re-treated with PSL at 5 mg/day, eosinophil counts increased rapidly (829/mm3). The dose of CAM was accordingly doubled (800 mg/day), with the dose of PSL maintained at 5 mg/day. After 4 weeks, the eosinophilic count had improved (78/mm3). By the end of the observation period, the doses of PSL and CAM were reduced to 4 and 600 mg/day, respectively, with normal eosinophil counts. Follow-up enhanced CT revealed the improvement of the thickening of the small intestinal walls and ascites (). Long-term use of CAM did cause slightly loose stool as a side effect.