How is parosmia treated?

Treatment of Parosmia

Modified olfactory training (MOT) is the primary evidence-based treatment for parosmia, particularly for COVID-19-induced cases, and should be initiated immediately and continued for at least 3-6 months. 1, 2

Primary Treatment Approach

Modified olfactory training represents the cornerstone of parosmia management and has demonstrated effectiveness specifically for COVID-19-related parosmia as of 2022. 2 This involves:

• Systematic exposure to specific odors over an extended period (minimum 3-6 months of continuous training) 1
• Early initiation is critical—begin training as soon as parosmia is diagnosed rather than waiting for spontaneous resolution 1
• Patient counseling that recovery duration varies significantly, making supportive care throughout the journey essential 2

Supportive Management Strategies

Dietary Modifications

• Avoid trigger foods that commonly provoke parosmic distortions, particularly those containing thiols and pyrazines (these are the primary chemical triggers identified in recent research) 2
• Referral to a registered dietitian for comprehensive counseling on flavor enhancement strategies and expanding dietary options while avoiding unpleasant foods 1
• Use of additional seasoning and flavor enhancers may help promote adequate food intake in individual cases 1

Monitoring and Follow-up

• Re-evaluate at 1 month, 3 months, and 6 months after initiating olfactory training 1
• Refer to otolaryngology or specialized smell/taste clinic if no improvement occurs after 3-6 months of consistent training 1

Alternative Treatment Considerations

Hyperbaric Oxygen Therapy

• May be considered for COVID-19-related parosmia refractory to traditional treatments (olfactory training and steroids), though evidence is limited to case reports 3
• This represents an emerging option when standard approaches fail 3

Pharmacological Options

• Topical and systemic medications may be used in select cases, though specific agents are not well-defined in current literature 4
• Steroids represent a traditional treatment option, though effectiveness data is limited 3

Critical Clinical Pitfalls to Avoid

• Do not assume spontaneous resolution will occur quickly—parosmia can be prolonged, and active treatment should not be delayed 2
• Do not confuse parosmia with phantosmia (phantom smells without stimuli), as treatment approaches differ significantly; phantosmia requires etiology-specific management rather than olfactory training 2, 4
• Do not underestimate psychological impact—parosmia severely affects mental well-being, quality of life, and can lead to social withdrawal, emotional distancing, and anhedonia 5
• Address safety concerns related to inability to detect spoiled food or gas leaks 1

Natural History Considerations

• Parosmia has delayed onset averaging 3 months after initial infection, unlike other neurocognitive symptoms 6
• Unlike other long COVID symptoms, parosmia often decreases over time rather than persisting or worsening 6
• Many cases will naturally resolve, but active treatment with olfactory training should still be pursued rather than watchful waiting alone 4

When Imaging is Indicated

• Imaging is NOT routinely needed when there is clear temporal relationship to viral infection 1
• MRI orbits/face/neck should be reserved for cases with discordance between symptoms and examination findings, or when structural pathology is suspected 7