Smell and taste in children with simple obesity

In 30 children, aged 10-16 years and suffering from simple obesity, significantly lowered odour detection thresholds were noted. The thresholds were lower than the average for a given age group in around 20% of obese children in cases of odours stimulating olfactory nerve and in around 57% in cases of substances stimulating olfactory and trigeminal nerves. Odour identification thresholds were similarly affected, with identification of olfactory nerve plus trigeminal nerve stimulating odours affected more than twice as frequently. In 77% cases also the electrogustometric thresholds were found below the normal range values when anode was used as the stimulating electrode. The detected alterations may be linked to metabolic disturbances, which accompany simple obesity.     

Multiple chemical sensitivity worsens quality of life and cognitive and sensorial features of sense of smell

Multiple chemical sensitivity (MCS) is characterized by a loss of tolerance to a variety of environmental chemicals. Multiple chemical sensitivity is frequently triggered by exposure to chemical agents, especially insecticides. The aim of the study was to measure the sense of smell and quality of life in patients with MCS compared to the control group. We studied the sense of smell, both sensitive and sensorial characteristics, in female patients with MCS (n = 58, mean 50.5 ± 8.5 years) and healthy female volunteers without rhinosinusal pathologies (n = 60, mean age 46 ± 10.2 years). Olfactometry (Barcelona Smell Test 24/BAST-24), sinonasal symptoms (visual analogue scale/VAS 0–100 mm), and quality of life (Quick Environmental Exposure and Sensitivity Inventory/QEESI) were assessed. Multiple chemical sensitivity patients showed a significant impairment in smell identification (19 ± 12 %; p > 0.05) and forced choice (62 ± 18 %; p > 0.05), but not in smell detection (96 ± 4 %) compared to the control group. Multiple chemical sensitivity patients reported more odours as being intense and irritating and less fresh and pleasant when compared with the control group. Patients scored a high level (40–100) on QEESI questionnaire (symptom severity, chemical intolerances, other intolerances, life impact). In MCS patients, total symptom intensity (VAS/0–700 mm) score was 202 ± 135, while disease severity score was 80 ± 23. The most frequent symptoms were itching and posterior rhinorrhea. Multiple chemical sensitivity patients have an impairment in smell cognitive abilities (odour identification and forced choice, but not for detection) with increased smell hypersensitivity and poor quality of life.     

Le Nez du Vin—a quick test of olfaction

There is a need for a quick and inexpensive smell identification test. A six odour multiple choice smell test derived from Le Nez du Vin, a winetaster's kit, is described. One hundred and thirty-two subjects assessed a mean of 5.28 ± 1.18 odours correctly. There was a significant difference between those who considered themselves to have a normal sense of smell (n= 91), mean score 5.52 ± 0.76, and those who thought themselves hyposmic (n= 41), mean score 4.76± 1.68, (P < 0.001). No significant differences could be detected between the scores of smokers and non-smokers, nor those of males and females. Twenty-one patients performed both the Nez du Vin and University of Pennsylvania Smell Identification Test (UPSIT) in random order. Results of the two tests showed good correlation (r= 0.79, P < 0.001).     

A study of 30 odors panel smell identification test,smell detection threshold and University of Pennsylvania Smell Identification Test (UPSIT) in Thailand

ObjectivesThis study aims to evaluate the application of the University of Pennsylvania Smell Identification Test (UPSIT) in Thailand, as well as to conduct an odor detection threshold test using phenyl ethyl alcohol and a 30-odor smell identification test.MethodsThis study was conducted from May 2019 to March 2020. We included healthy volunteers without any olfactory complaints. All participants underwent the UPSIT, an evaluation of odor detection threshold, and a 30-odor smell identification test.ResultsOne hundred fifty participants were included in our study. The overall mean score on the UPSIT was 26.04 ± 6.59 points and ranged from 9 to 39.7. For participants aged under 60 years, the mean UPSIT score was 29.08 ± 4.67 points, while the mean score of those 60 years of age and over was 19.20 ± 4.97 points (mean difference of 9.88 points), a difference that was statistically significant (95% CI 8.23 to 11.53, p<0.0001). The mean lowest log value on the odor detection threshold test was -7.12 ± 1.64. This was -7.53 ± 1.05 in participants under 60 years of age and -6.20 ± 2.27 in those 60 years of age and over (mean difference of 1.33; 95% CI 0.80 to 1.86, p<0.0001). Items in the 30-odor smell identification test with correct response rates greater than 70% included fish sauce, banana, coffee, patchouli water, coconut, lemongrass, orange, ammonia, vinegar, tea leaf, Thai perfume, jasmine, pandan, curry, lime, durian, cola, corn, pineapple, strawberry, and grape.ConclusionsThis study identified the odor detection threshold, UPSIT scores, and suitable odors to use in smell identification in a Thai population.     

Validation study of the "Sniffin' Sticks" olfactory test in a British population: a preliminary communication

Clin. Otolaryngol. 2012, 37 , 23–27 Objective: The ‘Sniffin’ Sticks’ olfactory test contains pen‐like odour dispensing devices which are used to assess olfactory threshold, discrimination and identification. Odour identification is strongly dependent on familiarity with the odours and has an important cultural component which has limited the usefulness of other validated tests. The ‘Sniffin’ Sticks’ test was developed in Germany and is validated in other countries but not in the UK. This study aims to validate the applicability of ‘Sniffin’ Sticks’ in a local population. Design: Prospective controlled study. Setting: Rhinology or olfactory disorder clinic. Participants: About 82 subjects, 33 healthy volunteers with a reported normal sense of smell, and 49 patients with an impaired sense of smell presenting either at a rhinology or an olfactory disorder clinic. Each subject’s olfactory function was assessed using the ‘Sniffin’ Sticks’ test with a maximum score of 48. Main outcome measures: Threshold, discrimination and identification scores along with the combined olfactory score. Results: The mean age of the subjects tested was 46.7 years; 46 female and 36 male. In the patient group 36 were hyposmic and 13 anosmic. In the healthy volunteers group all subjects were normosmic. In the control group the mean combined olfactory score was 34.5 (±2.5). The mean combined score in the patients group was 20.8 (±7.4). Odour threshold scores were 3.7(±2.8) for patients (hyposmics and anomics) and 8.3(±1.8) for controls. In the identification test the controls mean score was 13.6 (±1.2) for while the patients’ mean score was 8.6 (±3.5). Conclusions: In our sample of the local population the combined olfactory and odour identification scores for healthy volunteers and patients with olfactory disorders are comparable with the normative data published on large samples of European populations. However, modification of a few of the distracters is recommended for British patients based on our findings.     

Amount of airflow required for olfactory perception in laryngectomees: a prospective interventional study

Clin. Otolaryngol. 2012, 37 , 28–34 Objectives: To determine minimum airflow rate required for olfactory stimulation in successfully rehabilitated laryngectomised patients after learning the polite yawning technique (PYT) and to confirm the hypothesis that sense of smell is rehabilitated once the nasal airflow is re‐established. Design: Prospective open interventional trial. Setting: Tertiary academic hospital. Participants: The study population comprised 100 laryngectomised patients. The control group consisted of 100 non‐laryngectomised patients of similar age and sex. Rhinomanometry was used to measure air flow in the right and left nostrils, respectively, while the Smell Diskettes Olfaction test (SDOT) was used to test each individual’s sense of smell. Main outcome measures: The primary endpoint was increasing the airflow, while the secondary endpoint was improvement in the Smell Diskettes Olfaction test score after learning the polite yawning technique. Results: The difference in the Smell Diskettes Olfaction test results before and after introducing the polite yawning technique was statistically significant (F = 53.077; P < 0.001). The number of accurately identified odours increased with each measurement. There was a significant difference among rhinomanometric measurements of airflow through the right (F = 65.002; P < 0.001) and left nostrils (F = 75.465; P < 0.001). Nasal airflow improved with each measurement. The minimum airflow required for olfactory stimulation in successfully rehabilitated patients was approximately 60 cm³/s. The control group had considerably better airflow in both nostrils than the laryngectomised group. The difference between the total number of rehabilitated (normosmic) patients (48%) in the laringectomised group and normosmic participants (56%) in the control group (z = 1.132; P = 0.129) was not statistically significant. Conclusion: The number of odours identified by laryngectomised patients increased with the volume of nasal airflow. The number of patients with rehabilitated olfactory function approximated the percentage of normosmic individuals in the non‐laryngectomised population. These findings confirm the hypothesis that sense of smell is rehabilitated once the nasal airflow is re‐established.     

Impact of antibiotics on smell dysfunction

ObjectiveViral or bacterial respiratory infections can cause long-lasting olfactory dysfunction. Antibiotic therapy is indicated in severe cases; however, it is unclear whether antibiotic use produces a positive, negative, or null effect on olfactory function. This retrospective study sought to determine whether antibiotic use has an influence on odor identification and detection threshold test scores of patients with smell dysfunction secondary to upper respiratory infections (URIs), lower respiratory infections (LRIs), or rhinosinusitis.MethodsData from a total of 288 patients presenting to the University of Pennsylvania Smell and Taste Center were evaluated.ResultsPatients with a URI etiology who had taken bactericidal antibiotics had lower detection thresholds than did patients who had not taken antibiotics (P < 0.023; analysis of covariance with age and time since infection onset as covariates). Moreover, thresholds were lower for bactericidal antibiotic users than for bacteriostatic antibiotic users with either URI (P = 0.023) or rhinosinusitis (P = 0.028) etiologies. No meaningful influences of antibiotics on the odor identification test scores were evident.ConclusionsThese findings, which need to be confirmed in prospective double-blind studies, suggest that bactericidal antibiotic therapy may be beneficial in mitigating, at least to some degree, chronic decrements in smell sensitivity due to URIs and rhinosinusitis.     

Smell and taste in drug addicts

The main objective of this study was to establish the degree of influence of various illicit drugs, taken into the body in different ways, on the senses of smell and taste. Other possible factors, that might have caused disturbances in normal functioning of both senses, were outlined. The studied group consisted of 48 drug addicts, between the age of 16 and 48 years, addicted to various illicit drugs for several years. Olfactory testing included two methods. First quantitative method described by Elsberg and Levy, modified by Pruszewicz, was used to establish the smell detection threshold. Then the University of Pennsylvania Smell Identification Test was used as a method for odor identification. The sense of taste was tested with the use of method described by Krarup and modified by Pruszewicz. The results showed disturbances in olfactory performance (combined in both method) in 52.1% of all drug abusers, and 16.7% of them were diagnosed with ageusia when the sense of taste was tested. The route of administration of illicit drugs proved to be a statistically significant factor that might have caused disturbances of smell perception and identification in the study group. Drug abusers who were taking drugs intravenously and those who smoked and inhaled various drugs had the most significant olfactory problems. Both means for assessing smell function were statistically compared and the results showed that approximately 75% of drug users with olfactory disturbances had olfactory problems in both tests.     

Olfactory function in patients with chronic rhinosinusitis before and after functional endoscopic sinus surgery

BACKGROUND: The olfactory loss in patients with chronic rhinosinusitis has been measured by different methods. However, the results have been variable and it is not clear whether functional endoscopic sinus surgery (FESS) significantly improves olfactory function. This study was performed to evaluate the influences of FESS on olfactory function in patients with chronic rhinosinusitis using three different types of olfactory tests. METHODS: Seventy patients with chronic rhinosinusitis were administered the University of Pennsylvania Smell Identification Test (UPSIT), a single staircase phenyl ethyl alcohol odor detection threshold test (STT), and a short-term odor memory/discrimination test a day before and 6 months after FESS. A questionnaire inquiring about the patients' self-perception of olfactory function was administered also. Independent ratings of the severity of chronic rhinosinusitis before FESS were established from CT scans. RESULTS: Fifty-two (74.3%) of the patients reported that their olfactory function was impaired before surgery, and 68.6% of the patients reported impaired olfactory function after surgery, a difference that was not significant. No meaningful changes in any of the olfactory test scores were noted 6 or more months after FESS. Preoperatively, small correlations between CT scores and the symptom scores (r = 0.278; p = 0.024), threshold scores (r = -0.27; p = 0.031), and UPSIT scores (r = -0.36; p = 0.003) were observed. CONCLUSION: In patients with severe rhinosinusitis, FESS had little impact on the ability to smell, regardless of the method for assessing smell function. Subtle associations between olfactory function and the severity of chronic rhinosinusitis determined by CT were observed, however, preoperatively. The olfactory test measures were correlated with one another both pre- and postoperatively.     

The smell map: is there a commonality of odour perception?

The normal perception of odour quality is poorly understood, so formulating meaningful tests of olfaction is difficult. While tests of odour discrimination and odour detection threshold have helped quantify olfactory dysfunction, there are not yet predictive relationships between sensitivity to particular odours and particular forms of olfactory dysfunction. Using 11 commonly encountered odours, 20 normosmics performed similarity ratings of odour pairs. Multidimensional scaling, a standard behavioural sciences data analysis method, was used to explore the perceptual relationships between the odours based on their pair-wise similarity ratings. Smell maps were created for each individual as was a common or archetypal map which indicated a commonality in individuals' odour perception, far greater than chance alone (P < 10(-6)). A preliminary analysis of four hyposmics suggests that they do not conform to the normosmic archetype. Future studies assessing the relationship between odours in the archetype should improve the selection of odours to be included in tests of odour discrimination.     

Lateralized differences in olfactory function

BACKGROUND: Birhinal testing of odor identification will not allow the detection of unilateral olfactory loss. The aim of the presented study was to evaluate side differences of odor identification in large groups of healthy subjects and in patients with nasal symptoms. PARTICIPANTS AND METHOD: Self-assessment of olfactory function and evaluation of olfactory function by means of a validated test were performed in 479 healthy subjects, in 765 patients with chronic rhinosinusitis (CRS), and in 53 patients with a tumor. A 12-item odor identification test ("Sniffin' Sticks") was used to evaluate olfactory function separately for each nostril. RESULTS: Fifteen percent of the healthy subjects demonstrated side differences in the identification of at least 3 out of 12 odors. Healthy elderly subjects showed larger side differences in identification of odor than younger ones; a general difference between odor identification with the right or left nostril was not found. Both CRS patients and patients with a tumor had larger side differences than healthy subjects. Only 20% of the patients with a tumor complained about impaired olfactory sensitivity, but more than 75% of them showed deficits in olfactory tests. CONCLUSION: Side differences of odor identification of 25% or greater should give reason for further investigation. Future studies are needed to investigate whether side differences in healthy subjects are a predicator of a higher risk for general olfactory loss.     

The smell map: is there a commonality of odour perception?1

The normal perception of odour quality is poorly understood, so formulating meaningful tests of olfaction is difficult. While tests of odour discrimination and odour detection threshold have helped quantify olfactory dysfunction, there are not yet predictive relationships between sensitivity to particular odours and particular forms of olfactory dysfunction. Using 11 commonly encountered odours, 20 normosmics performed similarity ratings of odour pairs. Multidimensional scaling, a standard behavioural sciences data analysis method, was used to explore the perceptual relationships between the odours based on their pair-wise similarity ratings. Smell maps were created for each individual as was a common or archetypal map which indicated a commonality in individuals’ odour perception, far greater than chance alone (P < 10 ^{1 - 6} ). A preliminary analysis of four hyposmics suggests that they do not conform to the normosmic archetype. Future studies assessing the relationship between odours in the archetype should improve the selection of odours to be included in tests of odour discrimination.     

Objective assessment of terbinafine-induced taste loss

OBJECTIVES: Terbinafine (Lamisil), a widely prescribed oral antifungal agent, reportedly induces taste loss in 0.6% to 2.8% of those taking the drug. However, many so-called taste problems reflect olfactory problems, and the sole empirical study published on this topic, based on whole-mouth testing of a single subject, found no terbinafine-related deficit. In this study, we quantitatively assessed, using well-validated taste and smell tests, chemosensory function in six patients complaining of taste disturbance after terbinafine treatment and compared their test scores to those of six age-, race-, and sex-matched normal controls. METHODS: Taste function was measured using a 96-trial regional test that assesses sweet, sour, bitter, and salty taste perception within the anterior (cranial nerve [CN] VII) and posterior (CN IX) lingual taste bud fields. Smell function was bilaterally evaluated using the 40-item University of Pennsylvania Smell Identification Test. RESULTS: Taste function for sweet-, sour-, and bitter-tasting stimuli was significantly depressed in both the anterior and posterior lingual regions. For sodium chloride, the decrements were confined to the posterior region. Olfactory function was within normal limits. CONCLUSION: These findings 1) support anecdotal case reports of taste loss after terbinafine use, 2) demonstrate that all four major taste qualities are affected, and 3) suggest that olfactory dysfunction is not involved. Because self-report markedly underestimates chemosensory deficits, more extensive quantitative testing of patients receiving terbinafine will likely reveal a much higher prevalence of terbinafine-induced taste loss than currently reported. Since being older than 65 years of age and having a low body mass index are reportedly risk factors for terbinafine-induced taste loss, physicians should be particularly on the alert for elderly persons taking this medication who may become depressed or alter their food intake in response to decreased taste sensation.     

Validation of the combined olfactory test

A new test of olfactory function, the combined olfactory test, has been designed to assess odours easily recognizable by the test population. The test consists of an odour recognition test of nine odours, where an odour in a bottle is chosen from a list of four possible odours in a forced choice manner. This is followed by a threshold test using a series of three-fold dilutions of l-butanol. The mean of the two scores is the combined olfactory score. The test was subjected to a validation study. It was performed on 133 participants with a normal sense of smell and a normal rhinological examination and on 94 participants who said that they did not have a sense of smell. There was a highly significant difference between the combined olfactory score in the normal and ‘anosmic’ groups (P < 0.001). This significant difference was the same between the two groups for the threshold and odour recognition arms of the test. There was a highly significant differece (P < 0.001) between the two subgroups of ‘completely anosmic’ and ‘almost anosmic’ participants, indicating that the test could grade the degree of olfactory dysfunction.     

Utility of a three-item smell identification test in detecting olfactory dysfunction

OBJECTIVE: Physicians rarely assess smell function, largely because of time considerations. Therefore, there is clinical need for very brief cranial nerve I screening tests. Although a few such tests exist, none have been adequately validated. The goal of this study was to empirically assess the utility of a three-item microencapsulated odor identification test in detecting olfactory dysfunction. SETTING: Smell and taste center at a university medical center. METHODS: The test was administered to 224 consecutive patients (98 men and 126 women ranging in age from 15-88 years). As part of their overall assessment, the well-validated 40-item University of Pennsylvania Smell Identification Test (UPSIT) was also administered. Sensitivity, specificity, and both negative and positive predictive values of the three-item test were established relative to UPSIT dysfunction categories. Test-retest reliability was determined in a subset of 39 patients. RESULTS: The three-item test was abnormal in 99% (67/68) of patients with anosmia, 85% (35/41) of those with severe microsmia, 76% (31/41) of those with moderate microsmia, and 50% (17/34) of those with mild microsmia. Of the 40 normosmic patients, 62.5% (25/40) correctly identified all odors, 25% (10/40) two odors, and 12.5% (5/40) one odor. None of the normosmic patients missed all three items. Using a cut-off score of 2, the test's sensitivity and specificity were 99% and 40%, respectively, for detecting total anosmia. The corresponding negative and positive predictive values were 98% and 43%. For detecting anosmia and severe microsmia, these values were 93%, 45%, 88%, and 63%. For detecting any olfactory pathology, they were 82%, 63%, 42%, and 91%. The test-retest reliability was 0.87. CONCLUSION: The brief three-item test used in this study was found to be highly sensitive in identifying olfactory loss in patients with chemosensory complaints, particularly those with severe dysfunction. Although only moderately specific, its high reliability and negative predictive value suggests it may be an appropriate screening test for olfactory loss.     

Evaluation of “Open Essence” odor-identification test card by application to healthy volunteers

Objective

In the United States and European countries, the University of Pennsylvania Smell Identification Test (UPSIT), the Quick Smell Identification Test (Q-SIT), a shorter version of the UPSIT, and “Sniffin’ Sticks” are widely used for testing olfaction. The odor stick identification test for Japanese (OSIT-J) has been manufactured in Japan. This was followed by the development of “Open Essence,” consisting of cards that make use of sealed odorants. This study examined the usefulness of Open Essence in young volunteers with normal olfaction.

Method

The participants were 176 medical students in their clinical clerkships at the Department of Otolaryngology, Kochi Medical School Hospital. There were 111 males and 65 females, with a median age of 24 years (range 22–42 years). The olfactory function of all participants was confirmed as normal by screening with T&T olfactometry. Before beginning Open Essence, the subjects were asked to answer a questionnaire on their olfaction and habits.

Results

Females had significantly better smell identification than males. Of the 12 odorants, “perfume” and “cooking gas” were difficult to identify, because perfume involves different imagery and the compounds that give the smell of gas are readily volatilized. In contrast, all participants recognized “curry” and “menthol,” probably because they are received as both somatosensory stimuli and smell.

Conclusions

These results suggest that, with improvement, Open Essence might be used for testing olfaction in Japanese subjects.     

Recovery of olfactory function following closed head injury or infections of the upper respiratory tract

OBJECTIVE: To investigate the outcome of olfactory function in patients with olfactory loss following infections of the upper respiratory tract (post-URTI) or head trauma. DESIGN: Retrospective patient-based study. SETTING: Smell and Taste Outpatient Clinic at a university hospital. PATIENTS: A total of 361 patients (228 women, 133 men) were included. MAIN OUTCOME MEASURES: Olfactory function was assessed using the "Sniffin' Sticks" test battery, which result in a threshold, discrimination, and identification score. The mean interval between first and last visit was 14 months. RESULTS: In comparing the overall threshold, discrimination, and identification scores between the last and first visit, olfactory function improved in 26% of the patients whereas it decreased in 6%. The cause of olfactory impairment had a significant effect on the recovery rate of olfactory function. Within the post-URTI group (n = 262), 32% of the patients improved, but in the posttraumatic group (n = 99) only 10% improved. In patients with post-URTI olfactory loss, a negative correlation was found between age and recovery of olfactory function. In general, the factor "sex" had no significant effect on recovery of smell function. CONCLUSIONS: To our knowledge, the series of patients presented herein is the largest in the literature to date in which standardized testing methods were used to assess the progression of impaired olfaction. It showed that the rate of improvement of olfactory function was significantly higher in patients with post-URTI dysosmia compared with patients with posttraumatic dysosmia. During an observation period of approximately 1 year, more than 30% of patients with post-URTI olfactory loss experienced improvement, whereas only 10% of patients with posttraumatic olfactory loss experienced improvement. Furthermore, age plays a significant role in the recovery of olfactory function.     

Sniffin’Sticks®: Ein neues Instrument zur Geruchsprüfung im klinischen Alltag

INTRODUCTION: The Sniffin'Sticks test battery consists of a short screening test and tests for odor detection thresholds (using n-butanol), odor discrimination and odor identification. We evaluated the usefulness of this new test in clinical practice and propose normative values. MATERIAL AND METHODS: In the present study 30 normosmic and 15 anosmic volunteers as well as 35 patients with various olfactory dysfunctions were examined. RESULTS: All four Sniffin'Sticks tests were able to separate normosmics and anosmics in a highly significant manner. Even a small decrease in olfactory performance was detectable in elderly patients. For practical purposes the sensitivity of the test for screening test was found to be too low. The good correlation between the individual Sniffin'Sticks tests and the correlation between the Sniffin'Sticks test battery and the "University of Pennsylvania Smell Identification Test" (UPSIT) test battery and the "University of Pennsylvania Smell Identification Test" (UPSIT) document the reliability of these tests. CONCLUSIONS: Our findings show that the Sniffin'Sticks are well suited to assess olfactory performance in clinical practice.     

Distorted olfactory perception: a systematic review

The sense of smell provides people with valuable input from the chemical environment around them. The human sense of smell generally fails in three ways; one is an intensity reduction and the other two are the quality of changes. Smell disorders can be classified into central or peripheral depending on their origin. Central causes can be related to an area of hyper-functioning brain cells generating this odor perception, thus olfactory distortions have also been observed with epilepsy and migraine. In this paper, we present a review of the current clinical understanding of olfactory distortions and discuss how they can be evaluated and therapies to treat this debilitating condition.