Excessive Dynamic Airway Collapse: A COPD/Asthma Mimic or a Treatment-emergent Consequence of Inhaled Corticosteroid Therapy: Case Series and Brief Literature Review

Excessive dynamic airway collapse (EDAC) is a clinical entity characterized by narrowing of larger airways during tidal breathing. Symptoms of EDAC can be similar to chronic obstructive airway disease (COPD)/asthma and EDAC can coexist with airway disease. More recently widespread use of inhaled corticosteroids (ICS) among patients with COPD/asthma has been implicated for the emergence of EDAC. In this report, we describe 6 adult patients presenting with chronic cough with a background diagnosis of either COPD or asthma on ICS, who were noted to have EDAC. We also made an attempt to briefly review the earlier published reports on EDAC. Our review suggested that EDAC is prevalent among patients with previous diagnosis of COPD/asthma and with ICS use. Female sex, older age, higher body mass index, and presence of gastroesophageal reflux disease (GORD), and chronic upper respiratory tract infections (URTI) may be a risk factor for EDAC. Chronic barking cough and shortness of breath are the common clinical presentation and acute presentation could be triggered by lower respiratory tract infection and episodic presentations can be related to chronic recurrent aspiration secondary to GORD or chronic URTI. Dynamic computed tomography of the chest and bronchoscopy are useful in the diagnosis. Pulmonary function tests could be variable, demonstrating normal, obstructive, or restrictive pattern. Management of EDAC with weight loss strategies, addressing GORD and URTI issues and antibiotics during acute lower respiratory tract infection may be helpful. Noninvasive positive pressure ventilation may be beneficial in some patients. ICS should be used wisely to prevent the emergence of EDAC among patients with chronic airway disease.