Direct Comparison of Quality of Life in Patients with Allergic Rhinitis Undergoing Sublingual Versus Subcutaneous Immunotherapy

<b>Background/Objectives</b>: Subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) are commonly used for allergic rhinitis (AR), yet limited research has directly compared their effects on quality of life (QoL). We aimed to assess QoL differences between SLIT and SCIT recipients. As both forms of immunotherapy have reported benefits, we hypothesize that patients undergoing SLIT and SCIT will have comparable QoL improvements. <b>Methods</b>: A cohort study included patients with AR treated with immunotherapy from 2018 to 2022. Patients with obstructive sleep apnea, primary ciliary dyskinesia, cystic fibrosis, vasculitis, rheumatoid arthritis, sarcoidosis, or lupus were excluded. QoL was evaluated using the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) at multiple time points. Demographics, additional therapies, and allergen sensitivities were recorded. Data were analyzed using SPSS Statistics. <b>Results</b>: A total of 41 participants were eligible for inclusion. Both SLIT and SCIT groups exhibited reductions from baseline RQLQ scores. Within SLIT recipients, 5/7 RQLQ domains significantly improved. SCIT recipients showed significant QoL enhancement in 3/7 domains. The mean difference between SLIT and SCIT cohorts was -0.18 (<i>p</i> = 0.57, <i>d</i> = -0.18, 95% CI [-0.79, 0.43] at a mean treatment time of 18 months. <b>Conclusions</b>: SLIT and SCIT showed comparable RQLQ score reductions after 18 months of therapy, suggesting similar QoL benefits between the two treatment paradigms. Further investigation is needed to explore SLIT vs. SCIT differences in long-term QoL improvements beyond two years.