Bronchite à éosinophiles

Eosinophilic airway inflammation may be encountered in asthma and in non asthmatic eosinophilic bronchitis, which is a recently identified and common cause of chronic cough. Non asthmatic eosinophilic bronchitis may be differentiated from asthma by the absence of airflow limitation and of bronchial hyperreactiveness (potentially reflecting the different localization of mast cells within the airway wall). Diagnosis is based on the confirmation of eosinophilic airway inflammation, usually by induced sputum, in the absence of other causes of chronic cough or of radiological and lung function abnormality. The cough is generally improved by inhaled corticosteroids. The long-term outcome is still not known; non asthmatic eosinophilic bronchitis may lead to the onset of fixed airway obstruction or asthma.