D3.182 - Initiating Sublingual Immunotherapy in Pre-Adolescence (

Local adverse events (LAEs) during the initiation phase of sublingual immunotherapy (SLIT) are a major cause of non-adherence, particularly in the pediatric population. It is hypothesized that age-dependent differences in sensory perception and psychological resilience may influence the tolerability of treatment. This study aims to evaluate the hypothesis that children under 12 years of age present a more favorable tolerability profile compared to adolescents, thereby creating better prerequisites for long-term adherence.

In this ongoing prospective observational study, we analyzed real-world interim data from 144 pediatric patients initiating SLIT. The cohort was stratified into two age groups: Group A (5–11 years, n=83) and Group B (12–18 years, n=61). Using a standardized patient-reported outcome (PRO) questionnaire, we assessed the incidence, localization, and subjective severity (VAS 1–10) of LAEs during the first month of treatment. Statistical analysis was performed using the Chi-square test for categorical variables and the Mann-Whitney U test for continuous variables.

Interim analysis revealed a high overall incidence of LAEs in both groups (54.2% in Group A vs. 63.9% in Group B; p = 0.23), confirming the class effect of SLIT. However, a distinct trend in localization was observed: adolescents reported oral paresthesia/itching more frequently than younger children (62.3% vs. 48.2%), reaching the level of a statistical trend (p = 0.093). Crucially, a dissociation between symptom prevalence and subjective burden was identified. Despite the higher frequency of oral symptoms, adolescents did not report a statistically higher mean Severity Score (4.42 vs. 4.18; p = 0.53) compared to children. Nevertheless, the Bother Rate (percentage of patients reporting symptoms as disturbing) was numerically higher in adolescents (19.7% vs. 15.7%). This suggests that comparable physiological sensations are perceived as more treatment-limiting in the adolescent population.

These preliminary findings indicate an "age-dependent tolerance gap". While physiological reactions are ubiquitous, pre-adolescent children (<12 years) demonstrate a numerically lower subjective burden and a higher threshold for discomfort compared to adolescents. Initiating AIT in this earlier window may be strategically advantageous for maximizing adherence. As this is an interim analysis, recruitment is ongoing to increase the sample size and further power these statistical observations.