[A case of chronic persistent cough caused by gastroesophageal reflux]

A 69-year-old female was admitted for the evaluation of chronic persistent cough of about six week duration which was particularly worse at night and did not respond to antibiotics or cough medicines. She did not smoke and had no history of allergies or abnormal inhalations. Eosinophil counts, serum IgE, CRP, titers of cold hemagglutinin (CHA), and antibody to mycoplasma were all within normal ranges. Chest X-ray films and respiratory function tests showed no abnormalities. Because of her complaint of mild heartburn, gastroesophageal reflux (GER) was thought to be a possible cause of her chronic cough. Upper gastrointestinal X-ray films revealed barium reflux up to the cervical esophagus, and gastrointestinal fiberoscopy showed reflux esophagitis. Bronchial biopsy specimens taken by fiberoptic bronchoscopy showed chronic inflammatory changes of bronchial mucosa with focal squamous metaplasia, mucosal basement membrane thickening, and lymphocytic infiltration in the submucosa. She made favorable progress following treatment with a histamine H2 blocker and cisapride for six weeks. She met Irwin's criteria and we concluded that her cough was caused by GER. We speculate that repeated tracheobronchial microaspirations of refluxed gastric acid may cause chronic inflammatory changes of the bronchial mucosa resulting in persistent cough.