Which wheezing preschoolers should be treated for asthma

Abstract Wheezing disorders in children under 5 years are common, but lack of clarity remains about which children should be treated to prevent symptoms and acute episodes. The aim of this review is to discuss a practical approach to deciding which children aged below the age of five years with asthma should be treated, and if so, with which strategy. The importance of having a clear definition of “asthma” for this age group, determined by a collection of presenting respiratory symptoms, without assumptions about underlying mechanisms is addressed. Subsequent consideration should be given to timing, severity and frequency of symptoms, together with assessment of objective biomarkers, including aeroallergen sensitization and blood eosinophils, to inform whether or not a preschooler with recurrent wheezing requires treatment. Numerous unanswered questions remain about the optimal management of non-allergic preschool wheezing and asthma, and areas of specific unmet need and future directions for research are highlighted.