Assessment of Smell and Taste in Patients with Allergic Rhinitis

We examined the senses of smell and taste in 240 patients with verified hypersensitivity reactions of the respiratory tract. Olfactometry was performed according to Elsberg and Levy's method and followed by electrogustometry. The examinations revealed that the incidence of smell and taste disorders in patients with allergic rhinitis is 21.4% and 31.2%, respectively. No significant relationships between smell and taste dysfunction were found. We evaluated statistically positive correlations between the olfactory and gustatory thresholds compared with 78 qualitative and quantitative factors assessed in the study. There was a statistically significant relationship between the olfactory thresholds and levels of eosinophils in blood and in nasal discharge, acid reaction of the nasal mucosa, coexisting nasal polyps and X-ray changes in the ethmoid sinuses. There was a positive influence of pharmacotherapy as well as specific desensitization and surgery on the impairment of the sense of smell in allergic rhinitis.     

Assessment of smell and taste in patients with allergic rhinitis

We examined the senses of smell and taste in 240 patients with verified hypersensitivity reactions of the respiratory tract. Olfactometry was performed according to Elsberg and Levy's method and followed by electrogustometry. The examinations revealed that the incidence of smell and taste disorders in patients with allergic rhinitis is 21.4% and 31.2%, respectively. No significant relationships between smell and taste dysfunction were found. We evaluated statistically positive correlations between the olfactory and gustatory thresholds compared with 78 qualitative and quantitative factors assessed in the study. There was a statistically significant relationship between the olfactory thresholds and levels of eosinophils in blood and in nasal discharge. acid reaction of the nasal mucosa, coexisting nasal polyps and X-ray changes in the ethmoid sinuses. There was a positive influence of pharmacotherapy as well as specific desensitization and surgery on the impairment of the sense of smell in allergic rhinitis.     

Olfaction in congenital hypothyroidism

The aim of the study is to present results of the olfactory testing in congenital hypothyroidism in the group of 20 subjects. The etiology of hypothyroidism included: Pendred's syndrome in 2 cases, hypoplasia in 2 cases, athyreosis in 5 cases and ectopy of thyroid gland in 11 cases. Olfactory testing involved olfactometry by Elsberg-Levy modified by Pruszewicz for 4 odorants: coffee, lemon, mint and anise; smell fatigability test by Pruszewicz et al. for lemon. Level of plasma TSH was determined in each subject. Age of the subjects, at which hormonal replacement therapy was started and regularity of the treatment were taken into consideration. Obtained results: impaired odorant identification and shortened smell fatigability period prove a significant impact of thyroid status on central nervous system development most probably already prior to birth and on cognition processes.     

Olfactory and gustatory disturbances caused by digitalism: a case report

It is known that an overdose of digoxin causes visual disturbance, but the effect on the senses of smell and taste is not known. A case of olfactory and gustatory disturbance caused by digitalism is reported. In a 62-year-old male patient suffering from chronic digitalism, the serum digoxin level rose to 6.0 ng/ml. The patient was diagnosed not only with visual disturbance but also hyposmia and hypogeusia. The patient recovered from visual and chemosensory disturbances after the serum digoxin concentration returned to normal. Because the similarity of intracellular signal transduction between photoreceptor cells and olfactory and/or taste receptor cells is known, it is suspected that the influence of digoxin to chemosensory organs was caused by intermediation of sodium–potassium–adenosine triphosphatase (Na–K–ATPase) of the chemosensory receptor cells.     

Differences between orthonasal and retronasal olfactory functions in patients with loss of the sense of smell

OBJECTIVE: To investigate differences between orthonasal and retronasal olfaction in patients with loss of the sense of smell without taste complaints. DESIGN: Electrophysiological and psychophysical testing of orthonasal and retronasal olfactory functions. SETTING: Outpatient clinics. PATIENTS: A series of 18 patients who had olfactory loss due to various reasons but no "taste" complaints. MAIN OUTCOME MEASURES: Orthonasal and retronasal olfactory functions assessed by olfactory event-related potentials and psychophysical smell tests. RESULTS: Psychophysical testing revealed retronasal olfaction to be normal or slightly altered, whereas orthonasal olfaction was either absent or severely compromised. Findings from nasal endoscopic examinations and computed tomographic scans were within the reference range in all subjects. In response to orthonasal stimulation there were neither detectable olfactory event-related potentials nor any with small amplitudes, whereas olfactory event-related potentials in response to retronasal stimulation were clearly present in some patients. CONCLUSION: These clinical observations, together with the psychophysical and electrophysiological findings, suggest that orthonasal and retronasal olfaction might be processed differently.     

Hearing loss, disorders of sound localization with the preservation ofsmell and taste in diabetics

Diabetes is often complicated by serious medical conditions which could be related to the development of auditory system and cranial nerves lesions, disorder of sound localisation and decreased olfactory and taste ability. Cranial nerve palsies in diabetes are considered as an integral part of the main disease. Twenty nine children with diabetes and non-diabetics control group, without a history of exposure to noise, ototoxic drugs, or ear disease aged 4-19 years old were examined. Hearing impairment may be present in children with disease duration above 3-5 years and in children with other complications. Sound localisation tests were performed by the method of Zakrzewski from a free auditory field, measuring the angle of directional hearing acuity in 35 diabetics age from 16 to 78 years. Longer duration of diabetes was associated with higher directional hearing acuity. Higher hearing loss was observed with higher directional values in diabetics. The authors investigated smell and taste in 35 diabetics. All patients were treated with insulin. Impairment value of smell identification thresholds was much more frequent than impairment of smell perception. In no case raised threshold of taste perception.     

Disorders of smell and taste

This article describes the anatomy and physiology of the gustatory and olfactory organs in man. Dysfunction of these senses is closely examined with respect to etiology, diagnosis, and treatment. Taste and smell are closely interrelated. An influence on the function of one sense often affects the function of the other sense.     

Drug-induced olfactory and gustatory dysfunction: Analysis of FDA adverse events reporting system

ObjectivesWith the COVID-19 pandemic, there is growing interest and research in olfactory and gustatory dysfunction (OGD). Drug-induced dysfunction is an often overlooked etiology. While several medications include smell or taste disturbance as a side effect, there are no publications describing which medications are most frequently implicated. We aim to describe the patterns of these adverse drug reactions (ADRs) using the FDA Adverse Events Reporting System (FAERS).MethodsThe FAERS database was queried from 2011 to 2021 for terms describing ADRs related to OGD. Terms included anosmia, hyposmia, olfactory test abnormal, olfactory nerve disorder, hallucination olfactory, parosmia, ageusia, hypogeusia, dysgeusia, and taste disorder. We identified the top reported medications associated with general smell dysfunction, general taste dysfunction, reduced smell, and altered smell.ResultsFrom 2011 to 2021, 16,091 ADRs were reported with OGD, of which13,641 (84.8%) and 2,450 (15.2%) were associated with gustatory and olfactory reactions, respectively. Zinc products (370 reports) and fluticasone propionate (214) were most commonly associated with olfactory dysfunction, specifically reduced olfaction. Varenicline (24) and fluticasone propionate (23) were most commonly associated with altered smell. Lenalidomide (490) and sunitinib (468) were most commonly associated with gustatory dysfunction. Antineoplastic and immunomodulating medications accounted for 21.6% and 36.3% of olfactory and gustatory ADRs, respectively. Among this category, immunoglobulin drugs were the most commonly associated with OGD ADRs.ConclusionGustatory dysfunction is more commonly reported ADR compared with olfactory dysfunction. Immunologic/rheumatologic medications are the leading culprit of reported OGD. With increasing numbers of patients presenting to otolaryngologists for OGD, it is important to consider drug-induced etiology.Level of evidenceIII.     

Olfactory dysfunction and its measurement in the clinic

The sense of smell is largely taken for granted by laypersons and medical professionals alike. Indeed, its role in determining the flavor of foods and beverages, as well as in warning of, or protecting against, environmental hazards, often goes unrecognized. This is exemplified, in part, by the fact that most patients presenting to medical clinics with “taste” problems are typically subjected to complex brain imaging and gastroenterological tests without the sense of smell even being tested or considered as a basis of the problem. Aside from frank deficiencies in sweet, sour, bitter, salty and savory (umami) sensations, “taste” disorders most commonly reflect inadequate stimulation of the olfactory receptors via the retronasal route; i.e., from volatiles passing to the receptors from the oral cavity through the nasal pharynx. This article describes the two most common procedures for measuring the sense of smell in the clinic and provides examples of the application of these tests to diseases and other disorders frequently associated with smell loss. Basic issues related to olfactory testing and evaluation are addressed. It is pointed out that smell loss, particularly in later life, can be a harbinger for not only a range of neurodegenerative diseases, but can be a prognostic indicator of early mortality.     

Barcelona Smell Test - 24 (BAST-24): validation and smell characteristics in the healthy Spanish population

OBJECTIVES: Smell tests for clinical use have been developed in different countries, but no single test has gained general acceptance. The objectives of the study were to evaluate the smell outcomes in a Spanish population. METHODS: A prospective study on healthy volunteers (n = 120) without olfactory disturbances was performed. The volunteers were differentiated by gender, age, and smoking habit groups. We used a new olfactory test, the Barcelona Smell Test 24 (BAST-24) that consists of 24 odours scoring smell detection, identification, and forced choice. RESULTS: Volunteers showed the highest scores on smell detection for both 1st (99%) and 5th cranial nerve (98%) odours. Spontaneous smell identification (54.7% and 59.3%) and forced choice (72.2% and 42.6%) scores were lower than those of smell detection, for both 1st and 5th cranial nerves respectively. On smell identification, volunteers scored higher in the left than in the right nostril. Females had better smell identification for both 1st and 5th cranial nerves (62.8%, 66.7%) than males (50.3%, 58.8%). Non-smokers had higher scores (65%) than smokers (59%) on smell identification for the 5th CN. CONCLUSIONS: For smell identification, females, non-smokers, and left nostril had higher scores than males, smokers, and right nostril respectively. BAST-24 is a good and reliable method to test the olfactory function in the clinical practice.     

Clinical study of flavor disturbance

OBJECTIVE: We have observed that, in cases of smell loss, patients often complain of taste loss as well even though they actually have normal gustatory acuity according to gustatory tests; we have defined such symptoms as "flavor disturbance". The clinical features of flavor disturbance are reported in this paper. MATERIAL AND METHODS: A total of 297 patients (99 males, 198 females; mean age 55.5 years) were treated for olfactory disturbance at the hospital of Hyogo College of Medicine between July 1995 and August 2001. Sixty-six out of 297 patients (22.5%) also experienced taste disturbance, and 49 of these 66 cases were evaluated by means of smell and taste tests. These 49 patients who complained of taste and smell loss were classified into two groups according to the results of their smell and taste tests. Patients who only complained of olfactory disturbance were also reviewed. RESULTS: There was no relationship between the severity of olfactory disturbance and the degree of flavor disturbance. The incidence of flavor disturbance was high in patients with sudden olfactory disturbance after upper respiratory tract infection or head trauma and low in those with slowly progressive olfactory disturbance. The symptoms of flavor disturbance improved regardless of whether smell was improved or not. CONCLUSIONS: The patients with flavor disturbance tended to misrecognize that they had taste loss because of sudden smell loss, and there were more of these cases than we expected. When patients with smell and taste loss are treated, flavor disturbance should also be considered.     

Disease manifestations in the otorhinolaryngologic region as the sequelae to side effects of drugs

The side effects of numerous drugs may lead to pathological changes or functional disturbances in the ENT region. In order to explain the causes of presenting symptoms, the ENT doctor should always take in consideration the various drugs which the patient is receiving but which have been prescribed by other specialists. This is pertinent particularly in pathological changes of the oral mucosa, impairment of salivary secretion, hearing, smell and taste as well as disturbances of tubal function and voice changes. The causative drugs and their mode action are discussed.     

Importance of unilateral examination in olfactometry

Hyposmia, the decreased sense of smell, and anosmia, the loss of sense of smell, may be unilateral or bilateral. If the olfactory acuity examined by means of bilateral test is normal, olfactory disorders are not found; unilateral examination is therefore necessary for definite evaluation of olfactory acuity. As evidence, 7 cases out of 94 patients with chronic rhinosinusitis and 6 cases out of 12 patients who received the surgery of anterior cranial fossa showed definite different olfactory threshold between nasal cavities, and there were no patients who recognized the diminished sense of smell in spite of unilateral high olfactory threshold. Additionally, we have experienced that a patient with brain tumor was diagnosed by the help of unilateral olfactory test. We thus strongly recommend the unilateral olfactometry as a method for simple and reliable test in clinical measurement of the sense of smell.     

The combined olfactory test in a Chinese population

OBJECTIVE: To establish an olfactory test in the Hong Kong Chinese population. STUDY DESIGN: Prospective analysis of the results of a combined olfactory test (COT) for patients with olfactory dysfunction and for normal subjects attending a secondary and tertiary ear, nose and throat centre. METHOD: Our COT was based on and modified from the Connecticut Chemosensory Research Centre test. It consisted of an odour identification test involving nine substances and a threshold test using a series of threefold dilutions of 1-butanol. From September 1998 to June 2002, 188 Hong Kong Chinese patients with olfactory dysfunction and subjects with normal olfaction were prospectively recruited. The subjects were categorized into normal, hyposmic and anosmic groups. The olfactory function of the main group of subjects (n = 153) was assessed with the COT by a blinded observer and also quantified with a visual analogue scale; the results were analysed to validate the discriminative ability of the COT. Another subgroup of subjects (n = 35) was tested with the COT twice with a two-week interval to evaluate test-retest reliability. RESULTS: There were 42 normal, 68 hyposmic and 43 anosmic subjects within the main group (total n = 153). The identification scores, threshold scores and combined olfactory scores were statistically significantly different between the anosmic, hyposmic and normal groups of subjects (p < 0.001). The combined olfactory score correlated with the visual analogue score and the correlation coefficient was 0.56 (p < 0.01). The mean time spent on each COT was 8.6 minutes (standard deviation = 3.4 minutes). The test-retest reliability of the COT was satisfactory, with a one-way model intraclass correlation coefficient of 0.87 (n = 35). CONCLUSION: The satisfactory discriminative ability and test-retest reliability of the COT have been demonstrated in this study. The COT is a feasible method for assessing sense of smell in the Hong Kong Chinese population.     

Clinical assessment of patients with smell and taste disorders

Clinical assessment of the patient who has smell and taste disorders requires understanding of the etiology of the olfactory and gustatory disorders. Available clinical tests of olfactory and gustatory systems allow detecting and measuring the degree of the sensory loss, but are unable to determine the cause and give neither prognostic information nor therapeutic guidance. With physical examination, however, clinical history can help to establish the diagnosis and guide the treatment if available. A clinician evaluating a patient who has smell and taste loss must understand that "taste" complaints usually are symptoms of an olfactory dysfunction. The distinction between true gustatory loss (bitter, sweet, salty, sour, or umami) and olfactory loss, the inability to perceive complex flavors of food, will help clarify the patient's diagnosis. Easy-to-administer tests are available for olfactory (eg, UPSIT) and gustatory testing (eg, spatial tests, taste sticks, tasting tablets). In rare circumstances, imaging studies (eg, MRI, CT) are indicated.     

Smell and taste disorders, a study of 750 patients from the University of Pennsylvania Smell and Taste Center

Smell and taste disorders are common in the general population, yet little is known about their nature or cause. This article describes a study of 750 patients with complaints of abnormal smell or taste perception from the University of Pennsylvania Smell and Taste Center, Philadelphia. Major findings suggest that: chemosensory dysfunction influences quality of life; complaints of taste loss usually reflect loss of smell function; upper respiratory infection, head trauma, and chronic nasal and paranasal sinus disease are the most common causes of the diminution of the sense of smell, with head trauma having the greatest loss; depression frequently accompanies chemosensory distortion; low body weight accompanies burning mouth syndrome; estrogens protect against loss of the sense of smell in postmenopausal women; zinc therapy may provide no benefit to patients with chemosensory dysfunction; and thyroid hormone function is associated with oral sensory distortion. The findings are discussed in relation to management of patients with chemosensory disturbances.     

The effect of chronic cocaine abuse on human olfaction

Cocaine has been used for many decades as both a stimulant and as a topical anesthetic/vasoconstrictor. Illicit "snorting" or freebase smoking has increased markedly in recent years. Decreased olfaction has been an often reported subjective complaint of cocaine abusers, but quantification of smell loss using sensitive psychophysical tests has not yet been done, leading to the present study. Eleven cocaine abusers were recruited from a drug treatment clinic. Olfaction was assessed using a butanol threshold test, the UPSIT, and a 7-item discrimination test. One patient tested anosmic, one had a mild discrimination problem, and one had a large septal perforation but was normosmic. From the present study, it appears that most cocaine abusers, even heavy users or those with intranasal damage, do not develop permanent olfactory dysfunction. It is not clear what factors may have resulted in complaints of olfactory loss in previous studies.     

Estimation of smell sense rehabilitation in patients after total laryngectomy

The loss of sense of smell significantly decreases a quality of life after total laryngectomy. That is why this problem should be considered within a complex rehabilitation of laryngectomized patients. The smell exercises ought to start parallely to the speech rehabilitation. The aim of our study was to estimate the efficacy of smell rehabilitation after total laryngectomy. 59 persons after total laryngectomy attending the fourteen days long rehabilitation camp were examined. All the patients had the examination of three smells identification (lemon, mint and anise) made before the beginning of exercises. All the persons had also the efficacy of air aspiration through the nose measured. The control examination of those parameters was conducted after fourteen days of exercises of making the negative pressure in the throat and nasopharynx directing the air flow into the olfactory area of the nose. We confirmed a statistically significant differences between the smell identification and the force of aspiration before and after rehabilitation. We confirmed that patient's age and the time from laryngectomy have the influence into the efficacy of smell rehabilitation.     

The effect of laser assisted uvulopalatoplasty on the sense of smell and taste

AIM: To assess the effect, if any, of Laser Assisted Uvulo Palatoplasty (LAUP) on the sense of smell and taste. MATERIALS AND METHODS: A prospective study examined 33 patients undergoing LAUP for snoring. Significant sinonasal pathology was excluded in all patients by a complete examination including rigid nasal endoscopy. None of the cases had any systemic illness or drug history that was likely to affect the sense of smell or taste. Twenty-eight patients were male and five female. The mean age was 44 years (range, 25-67). Twelve patients (36%) were regular smokers, and eight patients (24%) were ex-smokers all of whom reported a change in smell and taste after stopping. Preoperative assessment utilised a visual analogue score of smell and taste perception, the University of Pennsylvania Smell Identification Test (UPSIT) for the assessment of olfaction (maximum score of 40), and whole mouth testing for solutions of NaCl, sucrose, quinine, citric acid and acetic acid. LAUP technique was standardised for each case and reassessment was performed 3 months postoperatively. RESULTS: Three patients failed to complete the study and were excluded. The mean values for visual analogue score pre and post surgery were 9.1 and 8.9 respectively, which was not significant using Wilcoxon Rank test (P = 0.257). The mean value of the UPSIT scores before surgery were 32.3 (+4.0), range, 24-39, and after surgery 31.2 (+4.3), range 20-37. There was no significant difference in pre and post UPSIT scores (p = 0.068). Whole mouth taste testing had a preoperative mean value of 4.1 and a postoperative value of 4.2. The difference was not statistically significant, Wilcoxon Rank test (p = 0.317). CONCLUSION: In this study there was no significant change in the patients' perception of smell and taste or in their objective measurement following a standardised Laser Assisted Uvulopalatoplasty.