MANAGEMENT STRATEGIES FOR POSTVIRAL OLFACTORY DYSFUNCTION: A COMPREHENSIVE SYSTEMATIC REVIEW AND META-ANALYSIS

Abstract

Background:  Postviral olfactory dysfunction (PVOD) is a prevalent condition affecting millions globally, with significant impacts on quality of life, nutritional status, personal safety, and psychological well-being. Despite the high prevalence and clinical significance, optimal management strategies remain poorly defined, and treatment recommendations are heterogeneous across clinical centers. Objective:  To systematically review and quantitatively synthesize the evidence for medical and procedural management strategies in non-COVID-19 postviral olfactory dysfunction, providing evidence-based recommendations for clinical practice. Data Sources: Data were thoroughly searched in PubMed, Embase, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials (CENTRAL) since the inception of these databases until June 2026. Study Selection:  Studies were eligible if they have been randomized controlled trials, prospective cohort studies, or observational studies that assessed medical or procedural interventions in non-COVID-19 PVOD using objective olfactory outcomes. 46 studies were included out of the 871 records that were located. Data were extracted, and bias risk was assessed by two independent reviewers. The data was synthesized using random-effects meta-analysis, with standardized mean differences (SMD) serving as the primary effect measure. Main Outcomes and Measures:  The primary outcome was an increase in the scores on objective psychophysical olfactory tests like the UPSIT and Sniffin' Sticks TDI. Results:  The study encompassed 46 studies with more than 5,200 patients. The meta-analysis of 32 studies validated the effectiveness of olfactory training (OT) as most effective conservative intervention (SMD, 0.72; 95% CI, 0.51-0.93; P < .001). Adjusted OT protocols were better in efficacy (SMD, 0.88). There was a modest effect with topical corticosteroids (SMD, 0.35), and no evidence was strong enough with systemic corticosteroids, zinc sulfate, and minocycline. Sodium citrate (SMD, 0.60) and vitamin A + OT (SMD, 0.88) were promising. Procedural treatments, especially PRP (SMD, 0.78) and acupuncture (SMD, 0.82), demonstrated a strong potential in recalcitrant cases. Conclusions and Relevance:  Olfactory training remains the cornerstone of PVOD management. Pharmacological interventions should be tailored to specific clinical phenotypes. Emerging regenerative therapies represent promising frontiers for refractory postviral smell loss.