Early and longitudinal response to sublingual immunotherapy across pediatric allergic multimorbidity patterns: A 3-year real-world cohort study.

BACKGROUND: The timing of clinically meaningful benefit after pediatric sublingual immunotherapy (SLIT) across allergic multimorbidity patterns remains uncertain. We evaluated early and longitudinal response to SLIT in routine care. METHODS: This retrospective longitudinal cohort included patients aged 3-17 years who received individualized liquid-drop SLIT and met prespecified adherence and treatment-persistence criteria. Assessments were performed at baseline and months 6, 12, 18, 24, and 36. The primary outcome was achievement of the Pediatric Asthma Quality of Life Questionnaire (PAQLQ) minimal clinically important difference (MCID; increase ≥0.5 points) at month 6. RESULTS: Among 1208 patients, 1095 had asthma and 954 allergic rhinitis. Overall, 666/1095 (60.8%) achieved month-6 PAQLQ MCID: 515/671 (76.8%) with asthma plus allergic rhinitis (Asthma+AR), 103/254 (40.6%) with allergic asthma without AR, and 48/170 (28.2%) with asthma, AR, and atopic dermatitis (Asthma+AR + AD). Compared with allergic asthma without AR, adjusted odds of response were higher for Asthma+AR (adjusted odds ratio 4.73, 95% CI 3.47-6.45) and lower for Asthma+AR + AD (0.52, 95% CI 0.34-0.80). By month 36, mean PAQLQ increased by 1.42 points, rhinitis-related quality-of-life scores decreased by 1.89 points, FeNO decreased by 15.7 ppb, and prescribed inhaled corticosteroid dose decreased by 92.6%. CONCLUSION: Early response to pediatric SLIT differed across clinical allergic multimorbidity patterns, although outcomes continued to improve through 36 months in this selected adherent and treatment-persistent cohort.