Cough Variant Asthma

In Brief Cough is the most common complaint for which patients seek medical attention, and chronic cough is an especially important clinical problem. Guidelines for the diagnosis and treatment of cough have been published from several countries. Cough variant asthma is one of the most common causes of chronic cough throughout the world and comprises more than 40% of patients in Japan. It shares a number of pathophysiological features with classic asthma with wheezing, such as atopy, airway hyperresponsiveness, eosinophilic airway inflammation, and various features of airway remodeling, but presents solely with coughing. However, as many as 30% to 40% of adult patients may develop wheezing and progress to classic asthma, unless adequately treated. With respect to the diagnosis of cough variant asthma, responsiveness of coughing to bronchodilators (beta-agonist and theophyllines) is important. After the diagnosis is made, the first line treatment is inhaled corticosteroids, as established in classic asthma. This treatment improves cough and may also reduce the risk of progression to classic asthma, as has been shown by recent retrospective studies. Cough variant asthma should always be considered in the differential diagnosis of chronic cough, to prevent the development of wheezing, airway remodeling, and chronic airflow obstruction by early and long-term inhaled corticosteroid treatment. Cough variant asthma is one of the most common causes of chronic cough. It presents solely with coughing but shares many pathophysiological features with classic asthma with wheezing, such as airway inflammation and remodeling. Early treatment with inhaled corticosteroid is recommended, to reduce the risk of progression to classic asthma.