Comparison of Long-term Efficacy of Subcutaneous Immunotherapy in Pediatric and Adult Patients With Allergic Rhinitis

Purpose: Data comparing the long-term efficacy and safety of subcutaneous immunotherapy (SCIT) using house dust mite (HDM) in children and adults with allergic rhinitis (AR) are limited. This study aimed to compare the long-term effects of HDM-SCIT in a cohort of Chinese pediatric and adult patients with AR. Methods: A total of 124 pediatric and adult AR patients received HDM-SCIT for 3 years, with 118 patients being followed-up for 2 years. Prior to treatment (baseline), at the end of the 3-year treatment periods (third year) and 2 years after the discontinuation of treatment (fifth year), all patients were evaluated for total nasal symptom scores (TNSS), daily medication score (DMS), total combined score (TCS; symptoms [nasal + ocular] + DMS) and quality of life (QoL). Safety was assessed according to adverse events reported. Results: After 3-year treatment, HDM-SCIT significantly improved symptoms and QoL scores at the end of the third and fifth years in both groups. Better improvements were observed in the third and fifth years based on baseline, in children compared to adults (TNSS Delta 3: 6.66 vs. 5.41, P = 0.011; TCS Delta 3: 4.30 vs. 3.83, P = 0.027 and TNSS Delta 5: 6.16 vs. 4.86, P = 0.037; TCS Delta 5: 4.11 vs. 3.62, P = 0.044). Shorter duration of AR history before SCIT (<10 vs. >= 10 years) resulted in better improvements at the end of the third and fifth years (TCS Delta 3: 4.12 vs. 3.13, P = 0.036; TCS Delta 5: 3.90 vs. 3.09, P = 0.033). HDM-SCIT was safe and comparable in both children and adults with AR. Conclusions: Children with AR may achieve better long-term efficacy of HDM-SCIT than adults with AR.