Treatment‐Refractory Tracheobronchitis in Crohn's Disease: A Rare Pulmonary Manifestation of Inflammatory Bowel Disease

ABSTRACT Large airway inflammation is a rare and under‐recognised pulmonary manifestation of Crohn's disease. It is associated with significant morbidity and occurs independent of intestinal disease activity. Inflammation of the trachea and bronchi in inflammatory bowel diseases is typically responsive to corticosteroids or anti‐tumour necrosis factor agents. In this report, we present a case of tracheobronchitis in Crohn's disease presenting with a chronic productive cough while on adalimumab. The diagnosis was made by bronchoscopy, which revealed inflammation of the trachea and main bronchi, with biopsies demonstrating squamous cell metaplasia consistent with pulmonary inflammatory bowel disease. The patient was unable to be weaned off steroids and, in the presence of an elevated fractional expired nitric oxide, dupilumab was trialled, which resulted in minimal improvement in his symptoms.