Childhood Respiratory Conditions: Asthma.

Asthma is a heterogeneous condition characterized by airway hyperresponsiveness and inflammation that result in variable patterns of reversible airway obstruction with symptoms that vary over time. It occurs in approximately 10% of children. Symptoms typically are intermittent and include wheezing, cough, chest tightness, and dyspnea. In some young children, cough may be the only symptom. Symptoms commonly are caused by infections, exercise, allergens, or irritants. The diagnosis is based on a combination of history and physical examination findings and pulmonary function test results. Young children with symptoms similar to those of asthma with viral infections may or may not develop asthma; various scoring systems can predict the likelihood. For patients with asthma, controller drugs can reduce symptoms and prevent exacerbations. These drugs include inhaled corticosteroids, long-acting beta2-agonists that often are combined with inhaled corticosteroids, long-acting muscarinic antagonists, leukotriene receptor antagonists, and injectable biologics. Drugs are introduced in a stepwise manner, depending on age and severity of symptoms. Acute asthma exacerbations are managed with bronchodilators and oral corticosteroids. Patients with asthma and their families should have an asthma action plan to guide self-management. Physicians should ensure that patients are adhering to drug regimens and using inhalers appropriately. Environmental factors, such as allergens or cigarette smoke, can worsen symptoms and should be addressed.