Development of asthma
Seven studies aimed to investigate whether AIT is able to prevent the
occurrence of asthma in patients suffering from AR during the full
analysis and/or follow-up period (15,17–19,21,22,25,26). Most
assessments indicated that the risk of incident asthma was significantly
lower in patients with AR exposed to AIT compared with that in the
Non-AIT group regardless of the type of AIT (SCIT or SLIT), the
preparation studied (allergoid or natural allergen preparation), or the
type of allergen (HDM, birch or grass pollen, all allergens) for up to 9
years follow-up. Nevertheless, the results were not constantly
significant at certain analytical time periods (19,22), for single
preparations or preparation groups (22,26) or for the age group of
children (15). The only study comparing the risk in adults and
children/adolescents did not show a significant difference for follow-up
and full analysis periods (21). For details see tables S5, S6, S7, S8 in
supplementary information.