Eosinophilic Gastroenteritis: A Case of Mistaken Identity

Abstract

Introduction: Eosinophilic gastroenteritis (EG) is an uncommon disorder characterized by either local or diffuse eosinophilic infiltration of the gastrointestinal (GI) tract. Clinical presentation varies depending on the anatomical location and layer of the GI tract involved. We report a case of EG misdiagnosed as Common variable immunodeficiency (CVID). Case Report: A 23-year-old male diagnosed with CVID was referred for chronic diarrhea, abdominal pain, and hypoalbuminemia. He had recurrent bronchitis and sinusitis which led to his diagnosis of CVID. Monthly gammaglobulin infusions were started, however, the regimen was changed to every three weeks due to persistently low serum immunoglobulins. He denied drug and food allergies and had no other allergic conditions. Physical examination revealed 1+ pedal edema and was otherwise normal. Laboratory studies revealed a white blood cell count of 6.6 K/μl with absolute eosinophils of 1881 cells/μL (15-500), hemoglobin of 13.3 g/dl and platelets of 256 K/μl. Serum albumin was 2.8 g/dl and total protein was 5.4 g/dl. Serum IgG was 223 mg/dl (700-1600), IgA 58 mg/dl (70-400) and IgM 36 mg/dl (40-230). Autoimmune panel, quantiferon gold, celiac serology and stool studies were negative. Endoscopic evaluation found esophagitis, superficial erosions in the antrum, and duodenitis. Pathology revealed active gastritis with increased eosinophils >100/hpf and muscularis mucosa involvement, eosinophilic esophagitis with >58 eosinophils/hpf, and eosinophilic microabscesses. Helicobacter pylori was not identified. The duodenum exhibited aggregates of esoinophils in the lamina propria (16-18/hpf) with normal villous architecture. No evidence of parasites was noted. Prednisone 50 mg/day was started for EG with a taper by 10 mg every 4 weeks. At 8 week follow-up, he had normalization of his eosinophil count, serum albumin and immunoglobulins. Follow up endoscopy and biopsies of the stomach and esophagus were normal. Discussion: Eosinophilic gastroenteritis is a rare condition involving eosinophilic infiltrates in the gastrointestinal tract. Classification is based on maximal depth of tissue involvement: mucosal, muscle layer or subserosal layer. Clinical features vary based on the region and depth of eosinophilic infiltration. Current knowledge of treatment is derived mostly from small studies and anecdotal experience using dietary therapy, steroids, mast cell inhibitors, leukotriene receptor antagonists, surgery, and biologics. The natural history is not well described but clinical studies show that 40% patients have spontaneous remission without relapse after treatment and 50% have a more complex, chronic course characterized by unpredictable relapses.