Therapeutic options of post-COVID-19 related olfactory dysfunction: a systematic review and meta-analysis.

BACKGROUND: Olfactory dysfunction is a typical post-COVID-19 presentation, affecting patients' quality of life. There are currently multiple treatment options in this group of patients such as oral and intranasal corticosteroids, olfactory training, oral vitamin-mineral supplementation, amongst others. This meta-analysis aims to consolidate existing evidence for current therapies in patients with persistent olfactory dysfunction related to COVID-19 infection and evaluate the possible role of corticosteroid add-on therapy in olfactory training. METHODOLOGY: A systematic review and meta-analysis to study current treatments/interventions for olfactory dysfunction in post-COVID-19 infection were conducted. Data were pooled for the meta-analysis. The outcomes include subjective or objective olfactory assessment major and minor adverse reactions. RESULTS: Eleven studies (1414 participants) were included in this review, with six studies (916 participants) then assessed for the meta-analysis. Combined treatment of intranasal corticosteroid (INCS) with olfactory training (OT) has no benefit over OT monotherapy from both a VAS score improvement and identification component of Sniffin' Sticks test standpoint. In addition, there were no differences in improvement of TDI score between combined oral corticosteroid (OCS) with OT therapy compared to OT alone. Olfactory function was, however, significantly improved after OT. CONCLUSION: There were no significant differences in the improvement of olfactory scores in combination INCS+OT or OCS+OT therapies compared to OT monotherapy. However, there is improvement in olfactory function after OT.

Leukotriene receptor antagonist addition to intranasal steroid: systematic review and meta-analysis.

BACKGROUND: Intranasal corticosteroids (INCS) and leukotriene receptor antagonist (LTRA) have different mechanisms of action. The combination of INCS and LTRA (INCS+LTRA) are utilized to control the allergic rhinitis (AR) symptoms. The effects of this com- bination have not been made evident yet. METHODOLOGY: Randomized controlled trials studying the effects of INCS+LTRA vs INCS in monotherapy on rhinoconjunctivitis symptoms in patients with AR were included. Data were pooled for meta-analysis. The outcomes were nasal symptoms, ocular symptoms, disease-specific quality of life (QOL), and adverse events. RESULTS: Six studies (358 participants) met the inclusion criteria. There were no differences between INCS+LTRA and INCS mono- therapy on composite nasal symptom score, total daytime symptom score, total night time symptom score, disease-specific QOL and adverse events. The results favoured the effects of INCS-LTRA on ocular symptoms. CONCLUSIONS: The effects of the INCS+LTRA combination are not different from INCS in monotherapy in the improvement of both nasal symptoms and patient's QOL. The combination may, however, be better on improving ocular symptoms.