As-needed intranasal corticosteroid spray for allergic rhinitis: a systematic review and meta-analysis

Background: As-needed intranasal corticosteroid spray (INCS) is commonly used by patients with allergic rhinitis (AR) who have suboptimal symptom control. This systematic review aimed to assess the effectiveness of as-needed INCS for treating AR. Methodology: Systematic searches for randomized controlled trials studying the effects of as-needed INCS compared to regular INCS, as-needed antihistamine, or placebo were performed. Primary outcomes were total nasal symptom score (TNSS) and disease-specific quality of life (DSQoL). Results: Eight studies (882 participants) met the criteria. Regular use of INCS showed greater improvements than as-needed INCS in TNSS, DSQoL, nasal peak inspiratory flow, sneezing, and nasal congestion scores with small effect sizes. There were no differences between regular and as-needed INCS usage for ocular symptoms, symptom-free days, nasal itching, and rhinorrhea scores. As-needed INCS was superior to as-needed antihistamine and placebo with medium effect sizes. There were no differences in risk of adverse events between the groups in all three comparisons. Conclusions: Regular use of INCS improved total nasal symptoms score and DSQoL better than as-needed INCS. However, as-needed INCS improved TNSS better than as-needed antihistamine and placebo. The effects of as-needed INCS were closer to regular INCS usage than to placebo or as-needed AH usage.