What is the recommended workup and referral for prolonged loss of taste and smell in the elderly?

Workup and Referral for Prolonged Loss of Taste and Smell in the Elderly

For elderly patients with taste and smell loss persisting beyond 3 months, initiate olfactory training immediately while conducting a focused evaluation for reversible causes, and refer to otolaryngology if symptoms persist beyond 6 months despite therapy or if concerning features are present. 1

Initial Clinical Assessment

History and Physical Examination

• Confirm the duration and onset pattern: Determine if symptoms began acutely (suggesting post-viral etiology) or developed insidiously (suggesting age-related, neurodegenerative, or medication-related causes) 2, 3
• Assess temporal relationship to viral illness: Post-viral olfactory loss accounts for 20-25% of specialist clinic presentations, with COVID-19 causing dysfunction in 59-86% of infected patients 4, 1
• Medication review is critical: Drugs are the most common reversible cause, accounting for 21.7% of taste disorders in the elderly 5
• Evaluate for nasal/sinus disease: This represents the most common cause of olfactory dysfunction (30% of cases), requiring anterior rhinoscopy to assess for polyps, masses, or inflammation 6, 3
• Screen for neurodegenerative disease: Olfactory dysfunction is an early sign of Parkinson's disease and Alzheimer's disease, and is associated with increased mortality in the elderly 2, 7
• Assess nutritional status and zinc levels: Zinc deficiency causes 14.5% of taste disorders in elderly patients 5

Physical Examination Focus

• Perform anterior rhinoscopy to identify obstructing polyps, masses, or mucosal inflammation 2, 3
• Complete oral cavity examination for infections, dental disease, or ill-fitting dentures 3
• Conduct thorough cranial nerve examination to identify neurologic pathology 2

Diagnostic Testing

When to Order Imaging

• MRI with olfactory protocol is indicated if abnormal neurologic examination findings are present, trauma is suspected, or symptoms persist beyond 6 months despite olfactory training 1, 2
• CT sinuses may be helpful when nasal endoscopy suggests sinonasal disease 2
• MRI is NOT routinely indicated if there is a clear temporal relationship to viral infection without neurologic signs 1

Laboratory Evaluation

• Zinc levels should be checked given the high prevalence of deficiency in elderly patients 5
• Consider COVID-19 testing if post-viral etiology is suspected and timing is appropriate 8

Formal Olfactory Testing

• Standardized testing (e.g., UPSIT) is indicated in refractory cases or when dysfunction significantly impacts quality of life 1, 2
• Objective testing reveals higher dysfunction rates than self-reported symptoms (98.3% vs 35% in one study) 4

Treatment Approach

Immediate Intervention

• Start olfactory training immediately for all patients with symptoms persisting beyond 3 months, continuing for at least 3-6 months 1
• Olfactory training protocol: Sniff and focus on four strong-smelling substances (rose, eucalyptus, lemon, clove essential oils) for 20 seconds each, twice daily 1
• This is the primary evidence-based treatment and should not be delayed while awaiting specialist evaluation 1

Address Reversible Causes

• Review and modify medications when possible, as this is the most common treatable cause in elderly patients 5
• Treat sinonasal inflammation with steroids if inflammation is identified 3
• Surgical excision for obstructing polyps or masses 3
• Zinc supplementation if deficiency is documented 5

Safety Counseling

• Install smoke and gas alarms in the home 1
• Emphasize vigilance regarding food expiration dates 1
• Refer to support resources such as smell and taste disorder organizations 1

Referral Criteria to Otolaryngology

Refer if:

• No improvement after 3-6 months of olfactory training 1
• Nasal masses or polyps identified on examination requiring surgical evaluation 3
• Unilateral symptoms raising concern for neoplasm 2
• Abnormal neurologic examination findings 2
• Severe impact on quality of life warranting specialized testing and management 2

Follow-Up Schedule

• Re-evaluate at 1 month, 3 months, and 6 months after initiating olfactory training 1
• Consider neuroimaging only if symptoms persist beyond 6 months despite therapy 1

Common Pitfalls to Avoid

• Don't assume age-related decline without evaluation: While aging causes natural impairment, 30% of cases have treatable sinonasal disease and 21.7% are medication-related 6, 5, 3
• Don't delay olfactory training: This should begin immediately rather than waiting for specialist evaluation, as early intervention improves outcomes 1
• Don't overlook medication review: Elderly patients on multiple medications for chronic diseases are at highest risk, and periodic review is essential 5
• Don't miss neurodegenerative disease screening: Olfactory dysfunction may herald Parkinson's or Alzheimer's disease and warrants appropriate evaluation 2, 7
• Recognize that most "taste" loss is actually smell loss: Patients frequently confuse retronasal olfaction (flavor) with true taste, so focus evaluation on olfactory function 4, 3