Effect of Medical Therapy in Allergic Rhinitis: A Systematic Review and Meta-Analysis

Background Intranasal corticosteroids (INCS), oral antihistamines (POAH), and allergen-specific immunotherapy (ASIT) are widely used in the treatment of allergic rhinitis (AR); however, appraisal of treatment effect has been heterogenous, and few studies have interpreted these outcomes in context with measures of nasal airflow. Objective To provide a systematic review and meta-analysis of randomized placebo-controlled trials for common therapy classes for AR to assess standardized treatment effect on validated patient-reported outcomes and physiologic measures of airflow. Methods A systematic search was performed in PubMed, Scopus, OVID, and Cochrane library databases to identify randomized controlled trials meeting inclusion criteria. Treatment effects of INCS, POAH, and ASIT on total nasal symptom score (TNSS), visual analog scale (VAS), Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), and peak nasal inspiratory flow (PNIF) were analyzed by meta-analysis. Results Twenty-two studies with 4673 AR patients were identified, with 5 INCS, 8 POAH, and 9 ASIT trials. INCS improved TNSS (mean difference [MD] 0.90; P = .002) and PNIF (MD 13.31 L/min [P = .0007]. POAH improved quality of life assessed by RQLQ [MD 0.36; P < .001], but no improvement was found in PNIF. ASIT improved RQLQ [MD 0.65; P < .001], with a trend toward improvement in TNSS. Conclusion Overall, INCS resulted in a clinically and statistically meaningful improvement in symptom scores and physiologic measures in AR. POAH and ASIT both improved symptom scores and quality of life, but their impacts upon nasal airflow are uncertain. There is a lack of studies assessing the effect of INCS on quality of life and the effect of POAH on symptom severity, particularly for mild AR. Future studies should assess the effect of treatment for each of these patient-reported measures.