Publication:

Comparative efficacy of olfactory training versus combination therapy with oral corticosteroids in COVID-19 associated post-viral olfactory dysfunction

Background Post-viral olfactory dysfunction (PVOD) has emerged as a critical public health concern, amplified exponentially by the COVID-19 pandemic. While olfactory training (OT) is the current gold standard for rehabilitation, the additive role of systemic corticosteroids remains controversial, particularly for patients presenting late. This study aimed to compare the efficacy of classical OT alone versus a combination of oral corticosteroids and OT in patients with persistent PVOD.

Methods A prospective cohort study was conducted at the Department of Otorhinolaryngology in a tertiary care hospital in Mangalore between January 2021 and December 2023. We prospectively enrolled and analyzed 142 patients diagnosed with PVOD lasting >4 weeks. Group A received classical OT alone (n=72), and group B received a 14-day tapering course of oral corticosteroids combined with OT (n=70). Olfactory function was assessed using the "Sniffin’ sticks" test (TDI score) at baseline and 12 weeks post-treatment.

Results Both groups showed significant improvement in TDI scores (p<0.001). Group A improved from a mean baseline TDI of 16.4±4.2 to 21.8±5.1. Group B improved from 15.9±3.8 to 24.1±4.9. Inter-group comparison revealed a statistically significant greater improvement in group B (Combination Therapy) compared to group A (OT alone) (p=0.03). Clinically significant improvement (increase in TDI ≥5.5) was observed in 34.7% of group A and 48.5% of group B.

Conclusions While OT remains the cornerstone of therapy, a short course of oral corticosteroids in the persistent phase of PVOD offers significant synergistic benefits. This combination mitigates local neuroinflammation and yields superior olfactory recovery scores, even in sub-acute presentations.