Respiratory Conditions Update: Asthma.

Asthma is a chronic respiratory disease characterized by chronic airway inflammation and variable expiratory airflow limitation. Related clinical features include wheezing, dyspnea, chest tightness, and cough that worsens at night or in the early morning, and that varies over time and in intensity. A finding of variable expiratory airflow limitation on spirometry confirms the diagnosis. A forced expiratory volume in 1 second to forced vital capacity ratio less than the level predicted for the patient's age is suggestive of airflow limitation. Variability also must be confirmed. Updated guidelines recommend control-based management administered in a stepwise manner, with goals of achieving symptom control and minimizing the risks of exacerbations, future fixed airway limitation, and adverse effects of therapy. There is good evidence for the effectiveness of asthma education and self-management plans. Short-acting bronchodilators should be used as needed for symptom relief, with the addition of an inhaled corticosteroid early as maintenance therapy if symptoms are not well controlled. If asthma remains uncontrolled despite therapy, patients should be referred for more specialized treatment. Biomarkers, biologic drugs, and endoscopic treatments are being studied in the management of severe asthma, and ongoing research may determine which patients might benefit most from these emerging therapies.