Post-Traumatic Olfactory Dysfunction Management

Diagnosis and Assessment

Objective smell testing using validated tests, such as the North American UPSIT or Sniffin' Sticks, is recommended by the American Academy of Otolaryngology to diagnose post-traumatic olfactory dysfunction 1, 2
Nasal endoscopy is essential to rule out structural abnormalities or inflammatory conditions, and imaging studies like CT Maxillofacial or MRI Brain/Olfactory Bulbs may be indicated in certain cases, as recommended by the American Academy of Otolaryngology and the American College of Radiology 1, 3
Standardized psychophysical testing is mandatory, including assessment of odor threshold, odor discrimination, and odor identification, to determine the extent of olfactory dysfunction, with a strength of evidence aligned with guidelines from the American College of Physicians 2
The following imaging modalities are indicated for specific conditions:

Imaging Modality	Indication
CT Maxillofacial	Structural abnormalities, inflammatory sinonasal disease, history of trauma, or no improvement with initial treatment
MRI Brain/Olfactory Bulbs	Intracranial or skull base pathology, congenital anosmia, olfactory bulb volume assessment, or no obvious cause on endoscopy and CT

Inflammatory causes of post-traumatic olfactory dysfunction include chronic rhinosinusitis with/without polyps, allergic rhinitis, COVID-19, and other viral infections, with a prevalence of COVID-19-related anosmia ranging from 11.8-26.6% of cases 3, 2, 4
Structural causes include nasal polyps, tumors (sinonasal, skull base), and trauma-related damage, which may require surgical intervention 3
Neurological causes include post-viral olfactory dysfunction, head trauma, and neurodegenerative diseases (Parkinson's, Alzheimer's), which may present with anosmia as an early symptom 3, 2
Other causes include medication-induced, toxic exposure, congenital disorders, and aging-related decline, which should be considered in the diagnostic workup 3, 2

Olfactory training, involving repeated exposure to different odors, performed twice daily for at least 12 weeks, is recommended by the American College of Physicians as a first-line treatment for post-traumatic olfactory dysfunction 1
Intranasal corticosteroids, such as mometasone furoate nasal spray, are recommended at a dosage of 2 sprays in each nostril once daily for at least 3 weeks, and may improve outcomes when combined with olfactory training 1
Systemic corticosteroids, such as oral prednisolone, may be considered for severe cases with significant inflammation, at a dosage of 0.25-0.5 mg/kg for 1-3 weeks with tapering, as recommended by the American College of Physicians 1
Treatment approaches for specific causes include:

Approximately 30% of patients with post-traumatic olfactory dysfunction show improvement within 6 months, and recovery can continue for up to 2 years post-injury 1
Complete recovery is less common with more severe initial dysfunction, and some patients may have permanent deficits despite treatment 1
The combination of olfactory training and intranasal corticosteroids offers the best chance for improvement based on current evidence 1
Patients with persistent anosmia should be advised about installing gas and smoke alarms, checking food expiration dates carefully, and being cautious with gas appliances, as recommended by guidelines 5

Relying solely on patient self-report is inadequate, as objective testing is essential and patients frequently underestimate their impairment, a principle supported by the American Academy of Otolaryngology and Rhinology guidelines 2, 2
Missing serious underlying pathology, such as tumors or neurodegenerative diseases, which may present with anosmia, highlighting the need for comprehensive diagnostic approaches, as recommended by neurological societies and the American College of Radiology 3, 2
Inadequate imaging protocols, where CT and MRI must specifically evaluate the olfactory apparatus, is another pitfall, as would be advised against by radiological guidelines from the American College of Radiology 3
Failing to distinguish between smell and taste disorders, as patients often report "taste loss" when experiencing smell dysfunction, is a common error, as noted by the American Academy of Otolaryngology 2