Management of Preschool Children with Recurrent Wheezing: Lessons from the NHLBI's Asthma Research Networks.

Recurrent wheezing in the preschool children is a common clinical problem, often associated with significant morbidity related to acute episodes. The management of these children has been complicated by a paucity of high-quality clinical trials in this age group. To fill this knowledge gap, National Heart, Lung, and Blood Institute's asthma research networks have performed a series of clinical trials in an effort to provide practitioners with guidance on appropriate management strategies. These studies establish daily inhaled corticosteroid (ICS) therapy in toddlers at high risk for subsequent asthma as an effective approach for the prevention of exacerbations and symptom reduction, but without evidence of disease-modifying properties. Additional studies have confirmed substantial heterogeneity in ICS response, in terms of both efficacy and effect on linear growth. Treatment with intermittent high-dose ICS was demonstrated to be an alternative approach to daily low-dose ICS for preventing severe exacerbations in toddlers with intermittent but significant wheeze and a positive modified asthma predictive index. This review details the findings and clinical implications derived from these studies, discuss the utility of biomarkers and the role of oral corticosteroids during acute exacerbations, and summarizes ongoing clinical trials in this age group.