xRead - Olfactory Disorders (September 2023)

20426984, 2022, 4, Downloaded from https://onlinelibrary.wiley.com/doi/10.1002/alr.22929, Wiley Online Library on [04/09/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License

487

PATEL et al.

olfactory disorders. Several guidelines and multiple expert opinions suggest that the clinical history include the qual ity of olfactory changes, timing of onset, duration, asso ciated factors, and social and family history. 14,1034–1036 History of OD requires clarification on the quality of dysfunction (anosmia, hyposmia, dysosmia, parosmia, or phantosmia; definitions described in SECTION III: A– D), laterality (unilateral or bilateral), perceived degree of smell loss (partial or complete), and olfactory status before loss. Information on timing of onset and duration includes whether the patient ever had olfaction (congen ital or acquired), sudden or gradual onset, and whether the symptoms are persistent or intermittent. Patients may present with concurrent gustatory dysfunction. 135,914 Patients with OD frequently confuse symptoms of flavor loss resulting from the smell disturbance with true taste dysfunction. 135 Further clarification on whether patients have primary gustatory dysfunction or taste alteration attributable to an olfactory disorder with the preservation of basic taste perceptions (sweet, bitter, sour, and salt) is important. Factors associated with potential causes of the OD can be obtained from a history. Specifically, clinicians should obtain detailed history on sinonasal symptoms, infections, or traumatic events preceding the onset of OD, as these causes represent more than two thirds of patients pre senting with OD. Sinonasal factors to ask about include previous URI, sinusitis, allergy, nasal obstruction, and epistaxis. 147,225 OD during an acute URI or sinusitis can initially represent as conductive loss, but persistent dys function after resolution of infectious symptoms may indi cate sensorineural injury to the OE. 69,914 History of previ ous head trauma, nose/sinus surgeries, head and neck can cer, and radiation is important in determining the etiology of OD. 1037,1038 Loss of smell related to trauma more com monly presents with sudden onset and complete anosmia in comparison to URI-related dysfunction more commonly resulting in hyposmia. 50,69,135,914 The nature and severity of the traumatic injury and the time course can be obtained. History of previous septum or sinus surgery should be asked as associated partial and complete smell loss has been reported. 1039,198 Social history includes history of occupational and envi ronmental exposure to toxins and substance use (ie, alco hol, smoking, cocaine, and other inhalants). 982,1040 Clin icians should ask about exposure to toxins previously known to cause loss of smell including various metals (cad mium, chromium, manganese, mercury, aluminum, and lead), gases (formaldehyde, methyl bromide, and styrene), and solvents (toluene and paint solvents). 135 Tobacco smoking history along with other substance use should be obtained in the assessment of OD. 982 Other symptoms in relation to mental status changes, cognitive dysfunction, and psychiatric complaints associ

ated with depression, schizophrenia, and bipolar disor ders can be obtained from history. 27,1041–1043 About 50% to 90% of patients diagnosed with AD or PD are affected by smell loss. 558,1041–1044 OD has been identified as one of the early manifestations of the neurodegenerative diseases more commonly presenting with gradual onset hyposmia without obstructive symptoms. 1045–1047 Family history of neurodegenerative diseases and a complete medication list need to be additionally reviewed. Physical examination includes a full head and neck examination followed by nasal endoscopy, otoscopy, and neurological examination including cranial nerve examination. 14,23,69,135,137,914,1033 Initial anterior rhinoscopy with a nasal speculum can help in assessing anterior defor mities including obvious septal deviation and turbinate enlargement. Nasal endoscopy (rigid or flexible) allows for more thorough evaluation of the entire sinonasal area including posterior nasal cavity and nasopharynx. During nasal endoscopy, the OC and middle meatus should be carefully evaluated to rule out obstructive causes. 14,1048 Validated clinical scoring systems such as the Lund-Kennedy scoring system 1049 or the Olfactory Cleft Endoscopy Scale 1050 can be used to document the nasal endoscopy findings. Nasal endoscopy has been shown to be more sensitive than anterior rhinoscopy in detect ing nasal obstructive diseases. Seiden et al 137 found that OD with obstructive etiology was successfully diagnosed in 91% of cases with nasal endoscopy in comparison to 49% with anterior rhinoscopy. Use of intranasal anesthe sia before nasal endoscopy may affect chemosensory test results and the clinical history itself. Welge-Lussen et al 370 demonstrated that application of intranasal anesthesia reduces self-assessment of olfaction and odor discrimina tion among healthy volunteers. 370 Therefore, chemosen sory testing and obtaining the complete history should be performed before application of topical anesthetic. Oto scopy can be used to rule out obvious middle ear pathology that can affect the chorda tympani nerve and its associated taste impairment. 1051 For cases related to traumatic injury in acute settings, close inspection of laceration, ecchymo sis, and edema is advised to assess potential skull base and facial fractures that are associated with shearing or stretching injury of the olfactory nerves at the cribriform plate. 1052 Basic neurological and mental status examina tion can be considered if dementia or other neurodegener ative disorders are suspected. 14 Appropriate referral to spe cialists should be considered if either neurologic or neuro tologic causes are suspected. A complete history and physical examination, including nasal endoscopy, allows for appropriate diagnosis and management of OD. Aggregate grade of evidence : C (Level 4: six studies; Level 5: two studies).