Nonasthmatic eosinophilic bronchitis is a common cause of chronic cough. Etiology is unknown, although environmental exposures to dust, resin hardener, welding fumes, and formaldehyde have all been linked to the condition. Patients exhibit active respiratory tract inflammation and increased sputum eosinophils, differentiated from asthma based on the absence of bronchospasm.

Patients are typically in middle age. Attacks are typically brought on by exposure to an airway irritant such as dust. Coughing responds to inhaled or oral corticosteroids. While some studies suggest that it is a benign and self-limited disease, others hypothesize that the condition is a precursor to asthma.

Diagnosis requires demonstration of elevated eosinophils in the sputum or airway mucosa.