Immunotherapy
Allergen immunotherapy (AIT), either in the subcutaneous (SCIT) or
sublingual (SLIT) form, has long been shown to result in improved AR
control in all age groups and aspires to be the only etiologic treatment
for respiratory allergies (allergic rhinitis (AR) and asthma) through
induction of immunologic tolerance [126] [127]. Pooled analyses
support the complementary use of AIT on pharmacotherapy in AR patients
moreover due to achievement of long-lasting therapeutic effect
[128]. Recently, data from a real-world study confirmed the
medication sparing effect and long-term symptom relief following AIT, in
a cohort of grass AR patients, including children. In agreement,
subcutaneous allergoid immunotherapy in house dust mite AR children
resulted in significant reduction in AR and asthma medication, even
after long-term cessation of AIT [129].
Early-onset asthma is largely associated with IgE sensitization and AR
[130], thus AIT has long been suggested as a disease modifying
strategy potentially preventing allergen sensitization and asthma
occurrence in children with AR [131]. Although early clinical
studies showed a preventive effect of AIT on the occurrence of new
sensitizations in children with rhinitis [132], this is still
inconclusive [133]. A recent meta-analysis identified a short term
preventive effect of AIT on novel sensitization development;
nevertheless, the included studies were highly heterogenous [134].
Nevertheless, the preventive effects of AIT on asthma development and
progression has been confirmed in real-world studies, assessing the
effect of SLIT immunotherapy in grass pollen subjects with AR [135].
Moreover, a long-term randomized controlled trial, the Grazax Asthma
Prevention (GAP) study, [136], showed significantly lower and
long-lasting incidence of asthma following 3-year AIT in grass AR
subjects, while significant lower levels of total and allergen specific
IgE and reductions in skin prick test response to grass were noted
[137].