CCD: cross-reactive carbohydrate determinants, HDM: house dust mite, NSA: non-severe school-age asthmatic children, nsLTP: non-specific lipid transfer protein, NSRW: non-severe preschool recurrent wheezers, PR-10: pathogenesis-related protein family 10, SRW: severe preschool recurrent wheezers, TLP: thaumatin-like proteins