Search

Objectives: This study aimed to determine the characteristics of patients with qualitative olfactory dysfunction (qualOD) and whether individuals with parosmia exhibit increased olfactory sensitivity to previously reported odorous triggers of parosmia., Methods: This study included individuals aged ≥18 years, divided into quantitative OD only, parosmia, and phantosmia groups. Data collected included: clinical-demographic data, "Sniffin' Sticks" scores, questionnaires (depression scale, importance of olfaction), and information about parosmia and phantosmia. A proportion of patients underwent trigger odor threshold testing for 2-Furfurylthiol [FFT] found in coffee and 2,6-nonadienal [Nonadienal] found in cucumber., Results: Those with parosmia were typically younger women, with shorter OD duration due to post-viral OD (PVOD), hyposmic/normosmic, and experienced parosmia more severely. Parosmia was 3.5 times more likely in PVOD. Those with phantosmia were older, with longer OD duration due to idiopathic OD, hyposmic/anosmic, and experienced phantosmia less severely. There were no significant differences between FFT and Nonadienal threshold scores in patients with parosmia, phantosmia, or only quantitative OD, but all groups had significantly increased olfactory sensitivity for trigger odors compared to phenyl ethyl alcohol (PEA)., Conclusion: Parosmia and phantosmia patients have distinct characteristics. This may provide clinicians with a better understanding of possible olfactory outcomes in these patients. The higher olfactory sensitivity of all groups to trigger odors compared to PEA raises interesting points about parosmia triggers and odors in the context of warning for danger, in relation to the pathophysiology of parosmia that may be worth exploring in future studies., Level of Evidence: 3 Laryngoscope, 134:3277-3285, 2024., (© 2024 The Authors. The Laryngoscope published by Wiley Periodicals LLC on behalf of The American Laryngological, Rhinological and Otological Society, Inc.)

Objectives: Olfactory dysfunction (OD) is common and carries significant personal and societal burden. Accurate assessment is necessary for good clinical and research practice but is highly dependent on the assessment technique used. Current practice with regards to UK/international clinical assessment is unknown. We aimed to capture current clinical practice, with reference to contemporaneously available guidelines. We further aimed to compare UK to international practice., Design: Anonymous online questionnaire with cross-sectional non-probability sampling. Subgroup analysis according to subspeciality training in rhinology ('rhinologists' and 'non-rhinologists') was performed, with geographical comparisons only made according to subgroup., Participants: ENT surgeons who assess olfaction., Results: Responses were received from 465 clinicians (217 from UK and 17 countries total). Country-specific response rate varied, with the lowest rate being obtained from Japan (1.4%) and highest from Greece (72.5%). Most UK clinicians do not perform psychophysical smell testing during any of the presented clinical scenarios-though rhinologists did so more often than non-rhinologists. The most frequent barriers to testing related to service provision (e.g., time/funding limitations). Whilst there was variability in practice, in general, international respondents performed psychophysical testing more frequently than those from the UK. Approximately 3/4 of all respondents said they would like to receive training in psychophysical smell testing. Patient reported outcome measures were infrequently used in the UK/internationally. More UK respondents performed diagnostic MRI scanning than international respondents., Conclusions: To our knowledge, this is the most comprehensive UK-based, and only international survey of clinical practice in the assessment of OD. We present recommendations to improve practice, including increased education and funding for psychophysical smell testing. We hope this will promote accurate and reliable olfactory assessment, as is the accepted standard in other sensory systems., (© 2023 The Authors. Clinical Otolaryngology published by John Wiley & Sons Ltd.)

Objective: To determine if tokishakuyakusan (TSS) is effective for treating post-infectious olfactory dysfunction (PIOD) compared with vitamin B 12 (mecobalamin)., Methods: We conducted a randomized, nonblinded clinical trial. Patients with PIOD enrolled in 17 hospitals and clinics from 2016 to 2020 were randomly divided into two groups, and we administered TSS or mecobalamin for 24 weeks. Their olfactory function was examined using interviews and T&T olfactometry. The improvement of olfactory dysfunction was assessed following the criteria of the Japanese Rhinologic Society., Results: Overall, 82 patients with PIOD were enrolled in this study. In the TSS and mecobalamin groups, 39 patients completed the medication regimen. In the TSS and mecobalamin groups, olfactory dysfunction was significantly improved based on self-reports and olfactory test results. The improvement rate of olfactory dysfunction was 56% in the TSS group and 59% in the mecobalamin group. Early intervention within 3 months produced a better prognosis than the treatment initiated after 4 months. Furthermore, age and sex differences were not observed. Both medications produced no severe adverse events., Conclusion: The present study showed that TSS and mecobalamin might be useful for treating PIOD., Competing Interests: Declaration of competing Interest The authors have no funding, financial relationships, or conflicts of interest to disclose., (Copyright © 2023. Published by Elsevier B.V.)

Purpose: Olfactory dysfunction occurs after laryngectomy due to the loss of nasal airflow and inability to sniff. However, the reason for the loss of olfactory function after laryngectomy is unclear on evaluation with sniffing type tests performed individually. It is expected that the sensorineural olfaction remains, and the results of the sniffing test would be negative, while that of the odour-blowing test would be positive. Therefore, the aim of this study was to investigate both tests and prove normal olfaction in the patients., Methods: Patients who had undergone laryngectomy were evaluated using the T&T olfactometer for odour-sniffing tests, Jet Stream Olfactometer (JSO) for odour-blowing tests, and visual analogue scale (VAS). Evaluations were performed pre-operatively, and 1 month, 6 months, and 1-year post-laryngectomy., Results: Thirty-two patients were included in the study. The median recognition thresholds using the T&T and JSO were 1.4 and 2.2 before surgery, 5.8 and 5.4 at 1 month, 5.8 and 5.2 at 6 months, and 5.8 and 5.0 at 1 year after surgery, respectively. Results of the olfactory threshold test in both T&T and JSO and VAS score were significantly worse after surgery compared to that before laryngectomy (p < 0.05). The degree of increase was significantly smaller with JSO than with T&T (p < 0.05)., Conclusion: While we could not prove normal olfaction in patients after laryngectomy, the odour-blowing test was superior to the odour-sniffing test in detecting patients with residual olfaction. Simply blowing a scent is insufficient to obtain good olfaction; active airflow is crucial for recognizing odours., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Variability in human olfactory sensitivity has been attributed to individual-level factors such as genetics, age, sex, medical history of infections and trauma, neurogenerative diseases, and emotional disorders. Scarce evidence exists on the cross-cultural variation in olfactory sensitivity. Hence, we performed 2 studies to estimate the variability in olfactory threshold as a function of location and environment. Study 1 involved 11 laboratories from 4 continents (N = 802). In each location, in a designated laboratory, approximately 80 subjects underwent olfactory sensitivity testing with custom-made tests with eucalyptol and phenylethanol (PEA) odors. Tests were based on the Threshold subtest of the Sniffin' Sticks battery. In Study 2, we compared olfactory sensitivity and suprathreshold perception of PEA and eucalyptol in 2 Chinese (N = 160) and 2 Indian (N = 92) populations-one based in their native country and the other in Germany. Both studies present large-scale evidence that olfactory sensitivity varies as a function of geographical location and suggest that environmental factors play an important role in shaping olfactory sensitivity and suprathreshold olfactory perception. We delineate further steps necessary to identify specific factors underlying uncovered variability and the relationship between olfactory sensitivity and suprathreshold odor perception. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Objective: To assess olfactory function in children and to create and validate an odor identification test to diagnose olfactory dysfunction in children, which we called the Universal Sniff (U-Sniff) test., Study Design: This is a multicenter study involving 19 countries. The U-Sniff test was developed in 3 phases including 1760 children age 5-7 years. Phase 1: identification of potentially recognizable odors; phase 2: selection of odorants for the odor identification test; and phase 3: evaluation of the test and acquisition of normative data. Test-retest reliability was evaluated in a subgroup of children (n = 27), and the test was validated using children with congenital anosmia (n = 14)., Results: Twelve odors were familiar to children and, therefore, included in the U-Sniff test. Children scored a mean ± SD of 9.88 ± 1.80 points out of 12. Normative data was obtained and reported for each country. The U-Sniff test demonstrated a high test-retest reliability (r 27  = 0.83, P < .001) and enabled discrimination between normosmia and children with congenital anosmia with a sensitivity of 100% and specificity of 86%., Conclusions: The U-Sniff is a valid and reliable method of testing olfaction in children and can be used internationally., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Japan's medical insurance covers only the intravenous olfaction test, which is invasive and painful, and the T&T olfactometry recognition threshold test, which is not commonly used. The alternative open essence (OE) test recently developed and has shown clinical utility. Using a cross-over technique, we compared the OE test to other olfaction tests, administering it to 122 Japanese subjects diagnosed with olfactory dysfunction. Subjects scored olfactory function using the visual analog scale (VAS) and the Japan Rhinologic Society Self-Administered Odor Questionnaire (SAOQ). They also took the Japanese standard olfactory test (T&T olfactometry) and intravenous olfactometry (Alinamin test). Statistically significant correlations were seen among scores, the OE, SAOQ, VAS, T&T olfactometry recognition threshold, and Alinamin test, further indicating the OE test's clinical olfactory function evaluation. Menthol should, however, be eliminated from the OE formulation lineup due to its strong carry-over effect.

Detailed quantitative studies on olfaction remain inadequate in patients with paediatric allergic rhinitis (AR). This study examined olfactory dysfunction in children with AR. From July 2016 to November 2018, children aged 6–9 years were recruited and grouped as AR (n = 30) or without AR (control group, n = 10). Odour identification was evaluated by the Universal Sniff (U-Sniff) test and the Open Essence (OE). The results were compared between the AR and control groups. Intranasal mucosa findings, nasal smear eosinophil counts, blood eosinophil counts, total immunoglobulin E (IgE) levels, Japanese cedar-specific IgE and Dermatophagoides pteronyssinus -specific IgE were evaluated in all participants. Additionally, the presence of sinusitis and adenoid hypertrophy in patients with AR was also evaluated by sinus X-ray examinations. The median U-Sniff test scores were not significantly different between the AR and control groups (9.0 vs. 10.0, respectively; p = 0.107). The OE score was significantly lower in the AR group than in the control group (4.0 vs. 8.0; p = 0.007, respectively), especially in the moderate-to-severe AR group versus the control group (4.0 vs. 8.0; p = 0.004). Furthermore, in the OE, the correct answer rates for 'wood', 'cooking gas' and 'sweaty socks' were significantly lower in the AR group than in the control group. Paediatric AR patients can reduce olfactory identification ability, and the degree may be associated with the severity of AR in nasal mucosal findings. Furthermore, olfactory dysfunction may slow down the response to 'emergency situations', such as gas leak. [ABSTRACT FROM AUTHOR]

This international study aimed to investigate cross‐modal associations between parosmic sensations and visual information, as well as explore potential cross‐cultural differences; 393 parosmia patients from Argentina, Germany, Japan, and the Philippines participated. The patients were provided with a 63‐color chart encompassing diverse hues and a 20‐shape chart containing polygonal and curved shapes. Their task was to choose one color and one shape that matched their parosmic sensations. Results indicated that patients generally associated their parosmic sensations with brownish or greenish colors, darker colors, and polygonal or cloud‐like shapes. Significant cross‐cultural differences were observed, with Germans tending to select darker colors and edged shapes, while Japanese preferred brighter colors and curved shapes. These differences appeared to be related to the intensity of parosmia, which was higher among Germans. The study suggests a cross‐modal relationship between olfaction and vision, while also highlighting the influence of cultural factors on parosmia perception. Practical Applications: The findings of this study have practical implications for understanding and managing parosmia symptoms, particularly in multicultural settings. Healthcare professionals can use the cross‐modal associations between olfactory sensations and visual information as a tool for assessment and diagnosis of parosmia patients. By considering the cultural background of patients, healthcare providers can better understand the nuances in their descriptions and interpretations of parosmic sensations. Additionally, the observed cross‐cultural differences in color and shape associations can inform the development of standardized assessment tools that are sensitive to cultural variations. This knowledge can enhance communication between patients and healthcare professionals, leading to more accurate diagnosis, personalized treatment approaches, and improved patient outcomes. Furthermore, the study highlights the need for cultural sensitivity in odor‐related research and the development of interventions for parosmia and other olfactory disorders. [ABSTRACT FROM AUTHOR]

Resection of the olfactory mucosa (OM) is sometimes unavoidable during surgery; however, it is not known whether the OM can completely recover thereafter. The aim of this study was to uncover whether the OM fully recovers after mucosal resection and describe the process of OM regeneration. 8-week-old male Sprague–Dawley rats (n = 18) were subjected to OM resection at the nasal septum; six rats were euthanized for histological examination 0, 30, and 90 days after surgery. Immunohistochemistry was performed to identify olfactory receptor neuron (ORN) lineage cells [mature and immature ORNs and ORN progenitors, and olfactory ensheathing cells (OECs)], as well as dividing and apoptotic cells. Squamous and respiratory metaplasia and inflammatory cell infiltration were also assessed. On day 30 after resection, the mucosa had regenerated, and mainly contained thin nerve bundles, basal cells, and immature ORNs, with a few mature ORNs and OECs. On day 90, the repaired nasal mucosa had degenerated into stratified squamous or ciliated pseudostratified columnar epithelia, with reducing ORNs. The lamina propria contained numerous macrophages. Partial regeneration was observed within 1 month after OM resection, whereas subsequent degeneration into squamous and respiratory epithelia occurred within 3 months. Given the poor persistence of ORNs and OECs, OM resection is likely to result in olfactory impairment. Overall, surgeons should be cautious not to injure the OM during surgery. [ABSTRACT FROM AUTHOR]