Pediatric asthma: Principles and treatment.

Approximately one-half of children with asthma present with symptoms before 3 years of age. The typical history describes recurrent episodes of wheezing and/or cough triggered by a viral upper respiratory infection (URI), activity, or changes in weather. When symptoms occur after a viral URI, children with asthma often take longer than the usual week to fully recover from their respiratory symptoms. Wheezing and coughing during exercise or during laughing or crying, and episodes triggered in the absence of infection suggest asthma. A trial of bronchodilator medication should show symptomatic improvement. The goal of asthma therapy is to keep children "symptom free" by preventing chronic symptoms, maintaining lung function, and allowing for normal daily activities. Avoidance of triggers identified by a history, such as second-hand cigarette smoke exposure, and allergens identified by skin-prick testing can significantly reduce symptoms. According to the 2007 National Asthma Education and Prevention Program (NAEPP) report, if impairment symptoms are present for >2 days/week or 2 nights/month, then the disease process is characterized as persistent, and, in all age groups, inhaled corticosteroids (ICS) are recommended as the preferred daily controller therapy. Montelukast is approved for children ages ≥ 12 months and is often used for its ease of daily oral dosing. Long-acting beta-2 adrenergic agonists should only be used in combination with an ICS. For more-severe or difficult-to-control phenotypes, biologic therapy has been developed, which targets the type of inflammation present.