Montelukast reduces peripheral blood eosinophilia but not tissue eosinophilia or symptoms in a patient with eosinophilic gastroenteritis and esophageal stricture

Background: Eosinophilic gastroenteritis (EG) is an uncommon entity of which the pathogenesis is unclear. As no controlled treatment trials exist, treatment of EG remains largely empiric. Limited results have been achieved with oral cromolyn, ketotifen, and other antihistamines. Oral corticosteroids are effective, but long-term use is complicated by side effects including growth retardation, diabetes, and osteoporosis. Objectives: We sought to determine whether treatment with montelukast would improve symptoms and decrease both peripheral blood and tissue eosinophilia (TE) in a patients with steroid-dependent EG for 20 years complicated by esophageal stricture. Methods: In an unblinded, n = 1 trial, we treated the patient for 5 months with montelukast (20 to 30 mg daily) while his baseline dose of prednisone (10 mg daily) was continued. Complete blood counts and symptoms were monitored weekly. Esophageal biopsies were obtained before and after 5 months of therapy with montelukast. After the posttreatment biopsy was obtained, montelukast was discontinued. Outcome measures included patient symptoms and peripheral and tissue eosinophil counts. Results: During treatment with montelukast, the mean peripheral blood eosinophil count fell from 5,064 cells/muL (average 28 determinations over 20 years; range 1,408 to 12,500 cells/muL) to 1,195 cells/muL (average 14 determinations over 16 weeks; range 556 to 2,193 cells/muL), a 76% reduction. The corresponding TE as calculated from esophageal biopsies was 31 eosinophils/high power field before and 70 eosinophils/high power field after treatment. The patient noted no appreciable improvement in esophageal symptoms. Conclusions: Montelukast dramatically reduced peripheral blood eosinophilia, but did not affect TE or symptoms in this patient with severe, long-standing EG complicated by esophageal stricture.