CONCLUSION
This study highlights the importance of BSM remodelling in the susceptibility of severe preschool wheezers to present subsequent exacerbations. The combination of the level of BSM remodelling with atopic dermatitis, age at first wheeze and the presence ofHaemophilus in the BALF allows to differentiate preschool wheezers from the three groups of exacerbation frequency (i.e ., No-Ex, Low-Ex and High-Ex). Mechanistic studies are required to better understand the pathophysiological mechanisms leading to BSM remodelling in this specific population as well as longitudinal studies to assess the long-term stability of such exacerbation groups and its consequences over time.