[Eosinophilic airway diseases presenting with isolated cough except for asthma]

Cough variant asthma (CVA), atopic cough (AC) and eosinophilic bronchitis without asthma (EB) are eosinophilic airway diseases presenting with isolated chronic cough. Among them, bronchodilators are effective only in CVA. Bronchial responsiveness, diurnal variation of pulmonary function and bronchomotor tone are mildly increased to intermediate levels between mild asthma and normal in CVA, but not in AC or EB. Cough sensitivity is heightened in atopic cough and probably in EB, but not in CVA. Bronchoalveolar lavage eosinophilia is present in CVA and EB, but absent in AC. As asthma onset has been recognized in nearly 30% patients with CVA, but not in AC, long-term inhaled corticosteroid therapy is recommended only in CVA.