A meta-analysis of randomized clinical trials (RCTs) revealed that sublingual immunotherapy (SLIT), subcutaneous immunotherapy (SCIT), intranasal glucocorticosteroids (INCS), intranasal antihistamines, and oral antihistamines may be effective and safe treatments for alleviating symptoms associated with perennial and seasonal allergic rhinitis.

The researchers sought to evaluate the effectiveness and safety of various treatment approaches for addressing allergic rhinitis, with a specific focus on triggers such as birch pollen, grass pollen, and house dust mites. A meta-analysis was conducted for each category of drugs and allergens, evaluating both their effectiveness and the occurrence of adverse events (AEs). The findings were then depicted as a therapeutic index (TIX-Score).

The analysis encompassed a total of 27 RCTs. The most favorable total effectiveness outcomes were noted for house dust mites with INCS, and grass pollen when using a combination of INCS and intranasal antihistamines in a single device, as well as for intranasal antihistamines alone. In the case of birch pollen, SLIT demonstrated clinically meaningful total effectiveness. When assessing the cumulative scores for efficacy and AEs, the highest TIX-Score was observed for the combination of intranasal antihistamines and INCS in a single device for grass pollen.

The examined treatment approaches could alleviate both seasonal and perennial rhinitis symptoms. Nevertheless, it's important to exercise caution when interpreting the results, as the presence of significant heterogeneity in some cases may be attributed to the possible existence of confounding variables in the control groups.