Kaditis et al. [37] and Castro-Rodriguez et al. [17] reviewed the literature on the efficacy of ICS in recurrent wheezing preschool children. Based on these systematic reviews, as well as a number of randomised, double-blind, placebo-controlled clinical trials published after this review was completed, it is concluded that continuous treatment with ICS decreases the number of days with symptoms among children with persistent wheezing, without preventing the need for hospitalisation [14] and had less wheezing/asthma exacerbations and improved their symptoms and lung function, respectively