Nonasthmatic eosinophilic bronchitis in an ulcerative colitis patient – a putative adverse reaction to mesalazine: A case report and review of literature

BACKGROUND Lung and airway involvement in inflammatory bowel disease are increasingly frequently reported either as an extraintestinal manifestation or as an adverse effect of therapy. CASE SUMMARY We report a case of a patient with ulcerative colitis controlled under mesalazine treatment who presented with chronic cough and hemoptysis. Chest computed tomography and bronchoscopy findings supported tracheal involvement in ulcerative colitis; pathology examination demonstrated an unusual eosinophil-rich inflammatory pattern, and together with clinical data, a nonasthmatic eosinophilic bronchitis diagnosis was formulated. Full recovery was observed within days of mesalazine discontinuation. CONCLUSION Mesalazine-induced eosinophilic respiratory disorders have been previously reported, generally involving the lung parenchyma. To the best of our knowledge, this is the first report of mesalamine-induced eosinophilic involvement in the upper airway.