How to reverse post-viral anosmia?

Treatment of Post-Viral Anosmia

Olfactory training should be initiated immediately and continued for a minimum of 3-6 months as the primary evidence-based treatment for post-viral anosmia. 1

Primary Treatment Approach

Olfactory Training (First-Line Therapy)

• Start olfactory training immediately upon diagnosis and continue for at least 3-6 months, as recommended by the European Rhinologic Society 1
• Patients should be referred to validated resources for proper training technique (such as www.fifthsense.org.uk) 2
• This intervention has moderate strength of evidence and represents the cornerstone of management 1

Initial Assessment Requirements

• Perform objective psychophysical testing using validated instruments (UPSIT or Sniffin'Sticks) rather than relying on patient self-assessment, as patients typically cannot accurately gauge their impairment severity 1
• Conduct rigid nasal endoscopy to differentiate between conductive and sensorineural causes 1
• Document temporal relationship to viral infection, associated symptoms (nasal obstruction, rhinorrhea, flu-like illness), and predisposing factors 1

Recovery Timeline and Prognosis

Expected Natural History

• Recovery occurs in 44-73% of COVID-19 patients within the first month, though some develop persistent dysfunction 2, 1
• Complete resolution was seen in 13% and partial resolution in 14% of patients, with mean time to improvement of 7.2 days in early reports 2
• Recovery typically takes place within a few weeks, but longer timeframes are possible 2
• One case series showed recovery by day 17 in one patient, while others had persistent dysfunction requiring ongoing management 2

Adjunctive Treatment Considerations

Corticosteroid Therapy (Limited Evidence)

• The evidence for systemic corticosteroids combined with intranasal steroid/mucolytic/decongestant solution is very uncertain based on one small study of 18 participants 3
• This study showed 5/9 participants in the treatment group achieved normal olfactory function (CCCRC score ≥90) compared to 0/9 in the control group after 40 days, but the confidence interval was extremely wide (RR 11.00,95% CI 0.70 to 173.66) 3
• Given the very low-certainty evidence, corticosteroids should not be routinely recommended as first-line therapy 3

Treating Underlying Sinonasal Disease

• Address any sinonasal inflammatory disease with appropriate medical or surgical management before or concurrent with olfactory training 1
• This is particularly important if nasal endoscopy reveals obstructive pathology 1

Follow-Up Protocol

Structured Monitoring Schedule

• Re-evaluate patients at 1 month, 3 months, and 6 months after initiating treatment 1, 4
• Repeat objective psychophysical testing at each follow-up visit to document changes objectively 1
• Refer to an otolaryngologist or specialized smell/taste clinic if no improvement occurs after 3-6 months of olfactory training 1, 4

Supportive Management

Dietary and Quality of Life Interventions

• Refer patients to a registered dietitian for counseling on flavor enhancement, additional seasoning, and expanding dietary options 1, 4
• Address safety concerns related to inability to detect spoiled food or gas leaks 4
• Provide counseling about the impact on quality of life, as persistent olfactory dysfunction can have profound effects 3

Common Pitfalls to Avoid

Diagnostic Errors

• Do not rely on patient self-assessment of olfactory function severity, as objective testing reveals much higher rates of dysfunction (98.3% by UPSIT testing even when only 35% reported complaints) 5
• Do not order unnecessary neuroimaging (CT/MRI) when there is a clear temporal relationship to viral infection and no red flag symptoms (facial pain, serosanguinous discharge, visual changes) 2, 4

Treatment Misconceptions

• Do not prescribe systemic corticosteroids routinely, as the evidence is very uncertain and limited to one very small study 3
• Do not delay initiation of olfactory training while waiting for spontaneous recovery, as early intervention is recommended 1
• Recognize that most "taste loss" actually reflects loss of retronasal olfaction (flavor perception) rather than true taste dysfunction 5

COVID-19 Specific Considerations

• Perform COVID-19 testing in all patients with sudden-onset olfactory dysfunction, especially during pandemic periods, as anosmia may be the sole presenting symptom 1, 4
• Advise self-isolation as recommended by the World Health Organization for patients with anosmia during active infection periods 5

Alternative Approaches (Emerging Evidence)

Integrative Medicine

• One case study reported complete recovery within 4 months using Ayurveda (Shadbindu taila nasya) combined with Traditional Chinese Acupuncture at specific points (GV.20, LI.20, Ex.1, H.7, LI.11, GB.8, GB.21, GV.25) 6
• However, this represents very low-quality evidence from a single case report and cannot be recommended as standard practice 6