Abstract

Nonasthmatic eosinophilic bronchitis (NAEB) is a common and treatable cause of chronic cough. It plays a role 10-30% of cases presented with chronic cough. The etiology of NAEB can be associated with exposure to an occupational sensitizer or to a common inhaled antigen. Although, it is characterized with eozinophilic inflammation like asthma, there are no symptoms and objective evidences of airway hyperresponsiveness or bronchoconstriction. The difference may be related to the localization of mast cells within the airway wall, which is the airway smooth muscle in patients with asthma, and epithelium in patients with nonasthmatic eosinophilic bronchitis. The diagnosis of NAEB requires assessment of airway inflammation in the induced sputum after other causes of cough have been excluded by clinical, radiological, and physiological assessment. Patients are improved symptomatically and have a significant fall in their sputum eosinophil and cough receptor sensitivity following inhale corticosteroid treatment. However, there are no data currently available concerning the dose and duration of inhale corticosteroid treatment. Cough due to NAEB can be transient, episodic, or persistent in cases without treatment. Some patients require oral corticosteroids.