What are the management options for a patient with dysgeusia?

Management of Dysgeusia

For patients with dysgeusia, management should focus on identifying and treating the underlying cause, with specific interventions including dietary modifications, topical treatments for oral symptoms, zinc supplementation when deficiency is present, and olfactory training for post-viral cases. 1, 2, 3

Identify and Address the Underlying Cause

Medication-Related Dysgeusia

• Review all current medications as the most common reversible cause, particularly chemotherapy agents, protease inhibitors (boceprevir, telaprevir), weight-loss medications (phentermine/topiramate ER), ACE inhibitors, antihistamines, and antibiotics 1, 4
• For protease inhibitor-associated dysgeusia (occurring in 37-45% of patients), continue treatment without dose reduction as dysgeusia typically does not require treatment discontinuation 1
• For phentermine/topiramate ER-related dysgeusia (affecting ~25% of patients), weigh continuation against therapeutic benefit, as this is a common but generally tolerable side effect 1

Nutritional Deficiencies

• Measure serum and urinary zinc levels using flameless atomic absorption spectrophotometry, as zinc deficiency impairs gustin synthesis (a parotid metalloprotein essential for taste receptor function) and affects neurotransmission of taste signals 1, 5
• Supplement zinc and vitamin A when deficiency is documented, as this may improve dysgeusia by correcting the underlying metabolic defect 1
• Assess for other micronutrient deficiencies common in liver disease, malnutrition, or chronic illness 1

Post-Viral Dysgeusia (Including COVID-19)

• Test for SARS-CoV-2 in all patients with new-onset chemosensory dysfunction, as 59-86% of COVID-19 patients develop taste and smell loss, with isolated anosmia occurring as the sole presenting feature in up to 22% of cases 6
• Initiate olfactory training immediately for post-viral dysgeusia persisting >3 months: have patients smell and focus on four strong-smelling substances (rose, eucalyptus, lemon, clove essential oils) for 20 seconds each, twice daily, continuing for at least 3-6 months 3
• Perform rigid nasal endoscopy to exclude obstructive sinonasal pathology (polyps, masses, inflammation) that may contribute to chemosensory dysfunction 6, 3

Neurological Causes

• Assess for cranial nerve dysfunction (facial VII, glossopharyngeal IX, vagus X nerves), particularly in patients with Miller-Fisher syndrome, polyneuritis cranialis, stroke, Parkinson's disease, or dementia 2, 7
• Consider brain imaging (MRI with olfactory protocol) only if neurological signs are present or symptoms persist beyond 6 months despite appropriate treatment 3

Symptomatic Management

Dietary Modifications

• Implement dietary modifications for all patients with dysgeusia, avoiding crunchy, spicy, acidic, or hot foods/drinks as appropriate for comfort 1
• Address nutrition impact symptoms that worsen intake: treat depression, pain, nausea, constipation, and excessive drowsiness with readily available pharmacological therapies (metoclopramide, antidepressants, opioids, laxatives) 1
• Monitor nutritional status closely, as dysgeusia is associated with significantly less lean body mass, higher fat mass, and reduced caloric intake 8

Topical Treatments for Oral Dysesthesia

• For moderate-to-severe oral dysesthesia (burning sensation, altered taste without visible oral changes), use high-potency topical steroids (gel or dental paste preferred) or viscous lidocaine as first-line treatment 1
• Consider gabapentin for patients with moderate or severe symptoms interfering with oral intake 1
• Hold immunotherapy if symptoms interfere with oral intake (grade 2) or cause disabling pain requiring tube feeding (grade 3) 1

Dry Mouth Management (When Present)

• Improve hydration and limit caffeine intake 1
• Use topical measures: water sips, saliva substitutes, moisture-preserving mouth rinses, toothpaste, or spray 1
• Employ salivary stimulants: sugarless chewing gum, lozenges, or candy 1
• For moderate-to-severe cases, consider prednisone 20-40 mg daily for 2-4 weeks then taper, or systemic sialagogues (cevimeline or pilocarpine) 1

Objective Assessment

Standardized Testing

• Perform standardized psychophysical testing (UPSIT or Sniffin'Sticks) to objectively quantify dysfunction, as patients commonly underestimate their impairment (one study showed 98.3% had objective dysfunction when only 35% self-reported complaints) 6
• Use forced-choice triple-scale technique to determine perception and identification thresholds for sweet, bitter, sour, and salt flavors 5

Laboratory Evaluation

• Obtain serum and urinary zinc levels, leucocyte alkaline phosphatase activity (zinc metalloenzyme), liver function tests, B12, folate, and serum protein electrophoresis 5
• In chemotherapy patients, consider that higher melphalan concentrations correlate with more severe dysgeusia and poorer caloric intake 9

Follow-Up Strategy

• Re-evaluate patients at 1 month, 3 months, and 6 months after initiating treatment 3
• Refer to otolaryngology or specialized smell/taste clinic if no improvement after 3-6 months of appropriate therapy 3
• Counsel patients on safety precautions: install gas alarms and smoke detectors, be vigilant about food expiration dates, and connect with smell and taste disorder support organizations 3

Common Pitfalls to Avoid

• Do not rely on patient self-report alone—objective testing reveals much higher rates of dysfunction than subjective complaints 6
• Never reduce boceprevir dose for dysgeusia management, as suboptimal dosing promotes resistant viral species 1
• Do not skip nasal endoscopy in persistent cases—visual inspection is essential to identify treatable sinonasal pathology 6
• Do not delay olfactory training—it should be initiated immediately for post-viral cases, not after waiting for spontaneous recovery 3