Predicting severe asthma exacerbations in children

Severe exacerbations negatively impact the quality of life and education of children with asthma, while also causing substantial healthcare costs. Preventing severe asthma exacerbations requires identifying patients at high risk, in order to develop personalized care protocols to prevent such exacerbations. In this review, we assess and discuss recently published data on risk factors and predictive tools for severe asthma exacerbations in childhood. Although few genome-wide association studies have focused on severe asthma exacerbations, one such study recently identified cadherin-related family member 3 (CDHR3, implicated on integrity of the airway epithelium), as a susceptibility gene for recurrent severe asthma exacerbations in young children. Viral infections cause the majority of severe asthma exacerbations in childhood, with particularly detrimental effects in atopic subjects. Other known or potential risk factors for severe asthma exacerbations include second-hand tobacco smoke (SHS), allergens, air pollution, obesity, vitamin D insufficiency, chronic psychosocial stress, and non-adherence to prescribed treatment. In spite of progress in our understanding of the pathophysiology of asthma, we lack reliable instruments or biomarkers to predict severe asthma exacerbations. To date, having had a recent severe asthma exacerbation remains the single best predictor of subsequent exacerbations in children, suggesting individual susceptibility. Thus, children who had a recent severe asthma exacerbation should be closely monitored, particularly before viral infections are likely to occur (as when school begins), so that their controller medications can be adjusted according to their asthma control. Moreover, SHS avoidance and adherence to controllers such as ICS deserve particular emphasis on high-risk children