Smell and taste disorders in childhood: Diagnostic challenges and significant impacts on a child's well-being.

AIM: Smell and taste are senses that contribute to a child's overall well-being. Disorders affecting these senses can impact a child's daily life from enjoying meals to detecting potential dangers through scent. The aim of this study is to describe patient characteristics and etiological causes of olfactory (OD) and/or gustatory disorders (GD) in children referred to a smell and taste clinic. Secondly, we aim to suggest a clinical work up. METHODS: Retrospective study where data were collected from 57 children who were referred consecutively to the University Clinic for Flavour, Balance, and Sleep; Department of Otorhinolaryngology (ORL), Head and Neck Surgery; Goedstrup Hospital, Denmark, for assessment due to OD/GD from January 2017 to May 2023. RESULTS: Most of the children had anosmia (60 %), whereas sensation of the basic tastes was intact in all but eight children (16 %). The lowest TDI scores were in children with congenital OD. The underlying etiology was congenital followed by postinfectious mostly related to Covid-19. Picky eating including anorectic traits were seen in 16 % of patients. CONCLUSION: The focus on smell loss in pediatric population is low, and probably does not adequately reflect either underlying prevalence in this group or the possible consequences on a child's well-being. Moreover, increased awareness of children's smell and taste loss is needed, as it may be associated with eating disturbances.

Disparities in seeking care for olfactory and gustatory dysfunction: A population analysis.

INTRODUCTION: Despite effects on quality of life from olfactory and gustatory dysfunction (OD and GD), screening practices are limited, and patients' self-reporting of symptoms remains the only way to understand the burden of chemosensory dysfunction (CSD). Using a large population-based database, we sought to understand factors leading to reduced likelihood of discussing CSD with a provider. METHODS: The 2013‒2014 National Health and Nutrition Examination Survey (NHANES) chemosensory protocol was queried for factors influencing discussion of OD/GD with a healthcare provider. Sociodemographic, comorbidity, and objective OD/GD testing results were assessed with a multivariate analysis. RESULTS: Out of 146.1 million US adults, there were an estimated 41.4 million individuals with self-reported OD/GD in the prior 12 months (28.3%). A total of 86.8% of participants did not discuss their problem with a healthcare provider. Men were about half as likely to speak with a healthcare provider (odds ratio [OR] 0.42; 0.26-0.66; p < 0.001) and those with a college education were about nine times more likely to discuss the problem compared to those with less than a ninth-grade educational achievement (OR 8.83; 1.86-41.98; p = 0.02). Those with objective confirmation of CSD were still unlikely to speak with a provider (OR 0.77; 0.44-1.33; p = 0.36). CONCLUSION: Men and those with less education are less likely to discuss OD/GD with a healthcare provider. These populations tend to be at increased risk for CSD, and there are severe downstream health and quality of life implications related to CSD. Dedicated screening and increased public awareness are critical to ensure more equitable care.

Prevalence and factors associated with olfactory impairment among patients with acne treated with oral isotretinoin: a cross-sectional study.

OBJECTIVE: This study aimed to investigate the prevalence and factors associated with olfactory dysfunction in individuals exposed to Isotretinoin (ISO) for the treatment of acne, using the University of Pennsylvania Smell Identification Test (UPSIT®). METHODS: This cross-sectional study enrolled age and sex-matched patients with acne who were current users of oral ISO and unexposed controls without olfactory complaints. UPSIT® and a validated questionnaire (Nasal Obstruction Symptom Evaluation) were administered to evaluate nasal obstruction in patients exposed to ISO. RESULTS: A total of seventy patients were recruited, with 35 in the exposed group and 35 in the unexposed group, consisting of 18 males and 17 females in each group, aged from 17 to 47 years. The prevalence of olfactory dysfunction was higher in the exposed group compared to the non-exposed group (62.9% vs. 17.1%), yielding a Prevalence Ratio (PR) of 3.7 (95% CI 1.9-7.1). However, no participants were categorized as anosmia or severe hyposmia and the majority of dysfunction was mild hyposmia compared to moderate hyposmia (51.5% vs. 11.4%). Among the exposed individuals, gasoline, orange, coffee, and wood exhibited the highest rates of identification errors (≥54%). Olfactory function demonstrated a negative correlation with treatment duration (p = 0.01), cumulative dose (p = 0.02), and nasal obstruction (p = 0.02). CONCLUSIONS: Olfactory dysfunction was more prevalent among ISO users, despite the patients being unaware of the disorder. Olfactory changes were correlated with treatment duration, cumulative dose, and nasal obstruction. LEVEL OF EVIDENCE: Level 4.

Olfactory Impairment and Frailty: A Systematic Review and Meta-Analysis.

Importance: Olfactory impairment (OI) and frailty are prevalent conditions associated with aging, but studies investigating their association with each other have been discordant. Objective: To summarize current evidence surrounding the association between OI and frailty. Data Sources: PubMed, Embase, Cochrane Library, SCOPUS, and CINAHL from inception to November 28, 2023. Study Selection: This study included observational studies investigating the association between objectively or subjectively assessed OI and objectively evaluated frailty among adults. Data Extraction and Synthesis: Two independent authors extracted data into a structured template. Maximally adjusted estimates were pooled using a random-effects model, and statistical heterogeneity was evaluated using I2 values. Additional prespecified subgroup and sensitivity analyses were performed. This study used the Newcastle-Ottawa Scale for bias assessment and the Grading of Recommendations Assessment, Development and Evaluation framework for overall evidence quality evaluation. Main Outcomes and Measures: The primary outcome was the cross-sectional association between OI and frailty, for which the odds of frailty were compared between participants with and without OI. The secondary outcome was the cross-sectional association between frailty and OI, for which the odds of OI were compared between participants with and without frailty. Results: This study included 10 studies with 10 624 patients (52.9% female; mean [SD] age, 62.9 [9.6] years). The Newcastle-Ottawa Scale score of studies ranged from low to moderate. Grading of Recommendations Assessment, Development and Evaluation scores ranged from low to moderate. OI was associated with a 2.32-fold (odds ratio [OR], 2.32; 95% CI, 1.63-3.31; I2 = 0%) greater odds of frailty compared with individuals with healthy olfactory function. The odds of OI was progressively greater with categorical frailty status, with a 1.55-fold (OR, 1.55; 95% CI, 1.32-1.82; I2 = 0%), 2.28-fold (OR, 2.28; 95% CI, 1.96-2.65; I2 = 0%), and 4.67-fold (OR, 4.67; 95% CI, 2.77-7.86; I2 = 0%) increase in odds for individuals with prefrailty, frailty, and the most frailty, respectively, compared with robust individuals. The results demonstrated stability in subgroup analyses (geographical continent of study, objective vs subjective olfactory assessment) and sensitivity tests. Conclusions and Relevance: The results of this systematic review and meta-analysis suggest that there is an association between OI and frailty, with an increase in the odds of OI with worsening categorical frailty status among individuals with prefrailty, frailty, and the most frailty. OI may be a potential biomarker for frailty. Future studies could delve into whether OI may be a modifiable risk factor for frailty.

Impact of Nutritional Status on COVID-19-Induced Olfactory Dysfunction.

OBJECTIVE: Although olfactory dysfunction is one of the most common presenting signs of COVID-19 infection, little is known about which populations are most susceptible. The aim of this study is to evaluate the risk of COVID-19-induced chemosensory dysfunction in malnourished individuals. METHODS: The N3C database was queried for adults having positive COVID-19 test result, diagnosis of chemosensory dysfunction within 2 weeks of positive test date, and overnutrition or undernutrition (i.e., deficiency or excess of micro- and macronutrients) related diagnoses prior to COVID-19 infection. Individuals previously diagnosed with chemosensory dysfunction were excluded. COVID-19-positive adults without olfactory dysfunction were similarly analyzed. Statistical analysis was performed using odds ratio calculations (95% confidence interval [CI]). RESULTS: Of 3,971,536 patients with COVID-19, 73,211 adults were identified with a diagnosis of undernutrition and 428,747 adults were identified with a diagnosis of overnutrition prior to infection. Of those with undernutrition, 264 (0.36%) individuals were identified with a diagnosis of olfactory dysfunction within 2 weeks of infection. Of those with overnutrition, 2851 (0.66%) individuals were identified with a diagnosis of olfactory dysfunction within 2 weeks of infection. The calculated odds ratio for undernutrition and olfactory dysfunction was 0.731 (p < 0.0001, 95% CI [0.0647, 0.0825]). The calculated odds ratio for overnutrition and olfactory dysfunction was 1.419 (p < 0.0001, 95% CI [1.3359, 1.5081]). CONCLUSION: Overnutrition may increase the risk of COVID-19-related olfactory dysfunction, while undernutrition may slightly protect. While reasons are unclear, baseline differences in metabolic, inflammatory, and structural biochemistry deserve closer inspection. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:4338-4343, 2024.

Olfactory dysfunction in patients with type 2 diabetes mellitus.

BACKGROUND: diabetic complications and olfactory dysfunction (OD) in patients with type 2 diabetes mellitus (T2DM) seem related. This study aims to evaluate the prevalence of OD in T2DM patients and to analyze its relationship with diabetic complications. METHODS: 130 T2DM patients and 100 comparable controls were enrolled. Olfaction was evaluated using the Extended Smell Test (TDI) and the Italian brief Questionnaire of Olfactory Disorders â€" Brief-IT-QOD. T2DM patients were divided into: "Group 1" patients with no complications, and "Group 2" patients with at least one diabetic complication. Non-parametric tests were used. Machine learning algorithms were applied to explore which variables were most important in predicting the presence of OD in T2DM. RESULTS: The prevalence of OD was significantly higher in Group 2 than in controls (71.4% vs 30%) and in Group 1 (71.4% vs 43.3%). However, when comparing the TDI scores between Group 1 and 2 the only significant difference was found for the discrimination scale and not for the identification and threshold scales. Brief-IT-QOD scores were significantly higher in Group 2 than in controls. The Random Forest and variable importance algorithms highlighted the relevance of LDL, glycated hemoglobin, type of complication (macrovascular) and age in determining OD in T2DM. The last three variables were included in a nomogram for the prediction of OD risk in T2DM. CONCLUSIONS: T2DM patients with diabetic complications are more frequently affected by OD. Poor glycemic control, LDL values, age and presence of macrovascular complications are the more important factors in determining OD in T2DM patients.

Neurofilament light chain is associated with olfactory dysfunction in US adults: findings from National Health and Nutrition Examination Survey.

BACKGROUND: Many individuals who have olfactory dysfunction are not aware of their impairment, which results in delayed detection of potentially hazardous situations. Simple and accurate methods for objectively assessing olfactory function are needed. In this study, we aim to investigate the utility of serum neurofilament light chain (NfL) levels as an indicator of olfactory dysfunction. METHODOLOGY: We analysed data on 1290 participants aged 40 years and older, who had valid data on olfaction and NfL level from the National Health and Nutrition Examination Survey 2013â€"2014. Multivariable modeling was used to investigate the relationship between olfactory dysfunction and NfL. RESULTS: Among 1290 participants, 174 participants had olfactory dysfunction based on the results of the NHANES Pocket Smell Test. In ordinal regression models, objective olfactory dysfunction was associated with NfL. After adjusting for age, sex, race/ethnicity, diabetes, smoking, olfaction-related medical history, Parkinson's disease and Alzheimer’s disease, the association remained significant. In logistic regression models, compared to participants with lower levels of NfL in the first tertile, those in the second and third tertiles had higher odds of objective olfactory dysfunction. There was no association between self-reported olfactory dysfunction and NfL tertiles. CONCLUSIONS: A strong association between objective olfactory dysfunction and serum NfL level was observed. NfL, independent of age, is a reliable marker indicating the development of olfactory dysfunction. The measurement of serum NfL level provides valuable support for assessment of olfactory dysfunction in clinical practice.

High prevalence of long-term olfactory disorders in healthcare workers after COVID-19: A case-control study.

BACKGROUND: More than a year after recovering from COVID-19, a large proportion of individuals, many of whom work in the healthcare sector, still report olfactory dysfunctions. However, olfactory dysfunction was common already before the COVID-19 pandemic, making it necessary to also consider the existing baseline prevalence of olfactory dysfunction. To establish the adjusted prevalence of COVID-19 related olfactory dysfunction, we assessed smell function in healthcare workers who had contracted COVID-19 during the first wave of the pandemic using psychophysical testing. METHODS: Participants were continuously tested for SARS-CoV-2 IgG antibodies since the beginning of the pandemic. To assess the baseline rate of olfactory dysfunction in the population and to control for the possibility of skewed recruitment of individuals with prior olfactory dysfunction, consistent SARS-CoV-2 IgG naïve individuals were tested as a control group. RESULTS: Fifteen months after contracting COVID-19, 37% of healthcare workers demonstrated a quantitative reduction in their sense of smell, compared to only 20% of the individuals in the control group. Fifty-one percent of COVID-19-recovered individuals reported qualitative symptoms, compared to only 5% in the control group. In a follow-up study 2.6 years after COVID-19 diagnosis, 24% of all tested recovered individuals still experienced parosmia. CONCLUSIONS: In summary, 65% of healthcare workers experienced parosmia/hyposmia 15 months after contracting COVID-19. When compared to a control group, the prevalence of olfactory dysfunction in the population increased by 41 percentage points. Parosmia symptoms were still lingering two-and-a half years later in 24% of SARS-CoV-2 infected individuals. Given the amount of time between infection and testing, it is possible that the olfactory problems may not be fully reversible in a plurality of individuals.

Smell loss is associated with cognitive impairment in amyotrophic lateral sclerosis patients.

BACKGROUND: Smell loss significantly impacts the quality of life in patients. However, there is limited research on smell loss in individuals with amyotrophic lateral sclerosis (ALS), and the correlation between smell loss and cognitive impairment is unclear. This study aimed to investigate the correlation between smell loss and cognition impairment in ALS patients. METHODS: The study included 216 ALS patients. The Edinburgh Cognitive and Behavioural ALS Screen (ECAS) and smell identification test specifically for the Chinese population (CSIT) were administered to evaluate participants' cognitive and olfactory function, respectively. RESULTS: After covarying for age, sex, BMI, education level, degree of hunger, dietary bias, eagerness for food, stress, smoking status, alcohol consumption, and upper respiratory tract infection (URTI) or rhinitis, CSIT scores were significantly correlated with ECAS scores (r = 0.162, p = 0.028), especially the ALS-specific scores (r = 0.158, p = 0.031). Even after excluding patients with URTI or rhinitis, the results were similar. CSIT scores were significantly correlated with ECAS scores (r = 0.224, p = 0.011), especially the ALS-specific scores (r = 0.205, p = 0.019). CONCLUSION: In patients with ALS, smell loss is significantly correlated with cognitive impairment, particularly frontotemporal dysfunction. Cognitive dysfunction may lead to worse olfactory performance in ALS patients.

The association between olfactory subdomains and frailty: A prospective case‒control study investigation.

BACKGROUND: Amidst the rise of frailty among a globally aging population, olfactory decline has emerged as a harbinger of frailty and mortality in population-level studies. However, the relationships between frailty and the olfactory subdomains of identification (OI), discrimination (OD), and threshold (OT) remain unexplored. This study prospectively examined the association between olfactory subdomains and the physical frailty phenotype (PFP) to investigate olfactory evaluation as a means of frailty screening. METHODS: A case‒control study of 45 frail and 45 non-frail individuals matched by age and sex. OT, OD, OI (range 0‒16), and composite sum (threshold, discrimination, and identification scores [TDI], range 0‒48) were measured with Sniffin' Sticks. PFP was defined by presence of three or more criteria: physical inactivity, self-reported exhaustion, muscle weakness, slow gait, and unintentional weight loss. Conditional logistic regression evaluated associations between olfactory subdomains and frailty. RESULTS: Ninety individuals with mean age of 83.1 ± 4.9 years, 60% female (n = 54), and 87.8% white (n = 79) were included. Olfactory scores were significantly lower in the frail group for OI (9.2 vs. 12.1, p < 0.001), OD (8.1 vs. 11.6, p < 0.001), OT (4.4 vs. 8.5, p < 0.001), and TDI (21.7 vs. 32.2, p < 0.001) than in the non-frail group. A single-point decrease in olfactory score was associated with increased odds of frailty in OT (odds ratio [OR]: 2.21, 95% confidence interval: [1.22, 3.98]), OD (OR: 2.19, 95% CI: [1.32, 3.65]), OI (OR: 2.29, 95% CI: [1.19, 4.39]), and TDI (OR: 1.54, 95% CI: [1.14, 2.08]). CONCLUSION: The robust association between olfactory subdomain scores and frailty suggests that olfaction may be an accessible signifier of frailty. Future studies should investigate this relationship longitudinally to assess predictive relationships.

Association of COVID-19 Vaccination With Changes in Smell and Taste.

Since the introduction of vaccines for severe acute respiratory syndrome coronavirus 2 in the United States, there has been significant vaccine hesitancy, in part due to fear of adverse effects. We sought to investigate the rates of smell and taste changes after COVID-19 vaccination compared to other common vaccines. Our study cohort included individuals identified by Current Procedural Terminology code in the TriNetX database receiving the COVID-19 first series, COVID-19 booster, influenza, tetanus, diphtheria, pertussis (TDAP), or pneumococcal vaccines between December 15, 2020, and August 15, 2023. After 1:1 propensity score matching, postvaccination incidence of disturbance of smell and taste was significantly less likely after COVID-19 first series vaccine compared to influenza (odds ratios, OR: 0.27 [95% confidence interval, CI: 0.20-0.36]), TDAP (OR: 0.35 [95% CI: 0.26-0.47]), and pneumococcal vaccines (OR: 0.17 [95% CI: 0.09-0.32]). Similarly, incidence of disturbance of smell and taste was significantly less likely after COVID-19 booster vaccine compared to the influenza (OR: 0.60 [95% CI: 0.48-0.76]), TDAP (OR: 0.63 [95% CI: 0.47-0.85]), and pneumococcal vaccines (OR: 0.44 [95% CI: 0.28-0.68]). This study builds upon the literature demonstrating the safety of COVID-19 vaccination.

Types of sensory disability are differentially associated with mental health in older US adults over time.

BACKGROUND: Sensory disability in older adults is associated with increased rates of depressive symptoms and loneliness. Here, we examined the impact of hearing, vision, and olfaction disability on mental health outcomes in older US adults. METHODS: We studied respondents from the first three rounds (2005/6, 2010/11, and 2015/16) of the National Social Life, Health and Aging Project, a nationally representative, longitudinal study of older US adults. Sensory function was assessed by structured interviewer ratings (hearing and vision) and objective assessment (olfaction). Cox proportional hazards models and one degree of freedom tests for trend were utilized to analyze the relationships between sensory disability and self-rated mental health, frequent depressive symptoms, frequent perceived stress, frequent anxiety symptoms, and frequent loneliness symptoms over time, adjusting for demographics, health behaviors, comorbidities, and cognitive function. RESULTS: We analyzed data from 3940 respondents over 10 years of follow-up. A greater number of sensory disabilities was associated with greater hazard of low self-rated mental health, frequent depressive symptoms, frequent perceived stress, and frequent loneliness symptoms over time (p ≤ 0.003, all). After adjusting for covariates, older adults with a greater number of sensory disabilities had greater hazard of low self-rated mental health (HR = 1.22, CI = [1.08, 1.38], p = 0.002) and loneliness symptoms (HR = 1.13, CI = [1.05, 1.22], p = 0.003) over time in our tests for trend. In our Cox proportional hazards model, older adults with vision disability had greater hazard of low self-rated mental health (HR = 1.34, 95% CI = [1.05, 1.72], p = 0.02) and loneliness symptoms (HR = 1.21, CI = [1.04, 1.41], p = 0.01). CONCLUSIONS: Older US adults with greater numbers of sensory disabilities face worse subsequent mental health. Future longitudinal studies dissecting the relationship of all five classical senses will be helpful in further understanding how improving sensory function might improve mental health in older adults.

Olfactory Impairment and the Risk of Major Adverse Cardiovascular Outcomes in Older Adults.

BACKGROUND: Olfactory impairment is common in older adults and may be associated with adverse cardiovascular health; however, empirical evidence is sparse. We examined olfaction in relation to the risk of coronary heart disease (CHD), stroke, and congestive heart failure (CHF). METHODS AND RESULTS: This study included 2537 older adults (aged 75.6±2.8 years) from the Health ABC (Health, Aging, and Body Composition) study with olfaction assessed by the 12-item Brief Smell Identification Test in 1999 to 2000, defined as poor (score ≤8), moderate (9-10), or good (11-12). The outcomes were incident CHD, stroke, and CHF. During up to a 12-year follow-up, 353 incident CHD, 258 stroke, and 477 CHF events were identified. Olfaction was statistically significantly associated with incident CHF, but not with CHD or stroke. After adjusting for demographics, risk factors, and biomarkers of CHF, the cause-specific hazard ratio (HR) of CHF was 1.32 (95% CI, 1.05-1.66) for moderate and 1.28 (95% CI, 1.01-1.64) for poor olfaction. These associations were robust in preplanned subgroup analyses by age, sex, race, and prevalent CHD/stroke. While the subgroup results were not statistically significantly different, the association of olfaction with CHF appeared to be evident among participants who reported very good to excellent health (HR, 1.47 [95% CI, 1.01-2.14] for moderate; and 1.76 [95% CI, 1.20-2.58] for poor olfaction), but not among those with fair to poor self-reported health (HR, 1.04 [95% CI, 0.64-1.70] for moderate; and 0.92 [95% CI, 0.58-1.47] for poor olfaction). CONCLUSIONS: In community-dwelling older adults, a single olfaction test was associated with a long-term risk for incident CHF, particularly among those reporting very good to excellent health.

Parosmia Is Positively Associated With Problematic Drinking, as Is Phantosmia With Depressive Symptoms.

OBJECTIVES: Alcohol use disorder (AUD) is a global health problem with significant negative consequences, including preventable deaths. Although olfactory dysfunction is associated with chronic alcohol drinking, the relationship among specific types of olfactory deficits, depressive symptoms, and problematic drinking remains to be explored. Here, we examined the prevalence of olfactory distortion (parosmia) and hallucination (phantosmia) and assessed their associations with problematic drinking and depressive symptoms. METHODS: In April-June 2022, 250 participants across the spectrum of AUD were recruited for assessment in the National Institute on Alcohol Abuse and Alcoholism COVID-19 Pandemic Impact on Alcohol study. Surveys covered self-reported olfactory function, depressive symptoms, and problematic drinking, with key measures assessed, including the Alcohol Use Disorders Identification Test and the Patient Health Questionnaire. Predictors in the analysis included parosmia and phantosmia, with covariates comprising age, sex, socioeconomic status, race, ethnicity, COVID-19 infection status, and smoking status. RESULTS: Among 250 individuals, 5.2% experienced parosmia and 4.4% reported phantosmia. Parosmia was associated with higher Alcohol Use Disorders Identification Test scores (ß = 7.14; 95% confidence interval = 3.31, 10.96; P < 0.001), whereas phantosmia was linked to higher Patient Health Questionnaire scores (ß = 3.32; 95% confidence interval = 0.22, 6.42; P = 0.03). These associations persisted in both the full sample and the subset of participants without COVID-19. CONCLUSIONS: Our study highlights strong existing links among olfactory deficits, problem drinking, and depressive symptoms, underscoring the need to assess smell impairments in clinical settings. Future research should explore these connections further to develop new treatments for individuals with AUD and depression.

Prevalence and Magnitude of Olfactory Dysfunction in Allergic Rhinitis.

BACKGROUND: Although allergic rhinitis (AR) can negatively impact the ability to smell, the degree to which this occurs is not clear and prevalence estimates vary among studies. This study had 4 main objectives: (1) To estimate the prevalence and the degree of olfactory dysfunction in AR patients; (2) To compare olfactory perception between AR patients with different persistence and severity of symptoms and determine if olfactory testing may aid in differentiating among Allergic Rhinitis and its Impact on Asthma (ARIA) groups; (3) To determine whether allergic reactions to different allergens differentially impact olfactory function, and (4) Verify possible changes in the olfactory epithelium (OE) caused by AR. METHODS: One hundred thirty-three patients with AR and one hundred controls were tested. The main outcome was the score in University of Pennsylvania Smell Identification Test (UPSIT®). The OE was examined using immunofluorescence markers for neuronal activity, apoptosis, oxidative stress, signal transduction, eosinophils, and epithelial thickness. RESULTS: Prevalence of olfactory dysfunction in the AR patients was higher (AR: 42.9% vs controls: 9%, P < .001). No difference was found either between intermittent and persistent disease cases (P = .58) or between cases with mild and those with moderate/severe symptomatology (P = .33). Lower olfactory capacity was not associated with the reaction to more (P = .48) or diverse types of allergens (Ps > .05). Although not significant, patients with AR had a greater amount of eosinophilia and a lower amount of cAMP (cyclic adenosine monophosphate) in the OE. CONCLUSION: The study highlights a higher prevalence of olfactory dysfunction in AR patients compared to controls, but olfactory testing may not effectively differentiate AR severity or allergen sensitivities. Although trends suggest potential pathophysiological changes in the OE of AR patients, further research is needed to validate these findings.

Establishment of a risk prediction model for olfactory disorders in patients with transnasal pituitary tumors by machine learning.

To construct a prediction model of olfactory dysfunction after transnasal sellar pituitary tumor resection based on machine learning algorithms. A cross-sectional study was conducted. From January to December 2022, 158 patients underwent transnasal sellar pituitary tumor resection in three tertiary hospitals in Sichuan Province were selected as the research objects. The olfactory status was evaluated one week after surgery. They were randomly divided into a training set and a test set according to the ratio of 8:2. The training set was used to construct the prediction model, and the test set was used to evaluate the effect of the model. Based on different machine learning algorithms, BP neural network, logistic regression, decision tree, support vector machine, random forest, LightGBM, XGBoost, and AdaBoost were established to construct olfactory dysfunction risk prediction models. The accuracy, precision, recall, F1 score, and area under the ROC curve (AUC) were used to evaluate the model's prediction performance, the optimal prediction model algorithm was selected, and the model was verified in the test set of patients. Of the 158 patients, 116 (73.42%) had postoperative olfactory dysfunction. After missing value processing and feature screening, an essential order of influencing factors of olfactory dysfunction was obtained. Among them, the duration of operation, gender, type of pituitary tumor, pituitary tumor apoplexy, nasal adhesion, age, cerebrospinal fluid leakage, blood scar formation, and smoking history became the risk factors of olfactory dysfunction, which were the key indicators of the construction of the model. Among them, the random forest model had the highest AUC of 0.846, and the accuracy, precision, recall, and F1 score were 0.750, 0.870, 0.947, and 0.833, respectively. Compared with the BP neural network, logistic regression, decision tree, support vector machine, LightGBM, XGBoost, and AdaBoost, the random forest model has more advantages in predicting olfactory dysfunction in patients after transnasal sellar pituitary tumor resection, which is helpful for early identification and intervention of high-risk clinical population, and has good clinical application prospects.

Long-COVID impacts taste and olfactory in individuals with substance use disorder: A retrospective cohort study from the TriNetX US Collaborative Networks.

Substance use disorder (SUD) exacerbates the impact of Long-COVID, particularly increasing the risk of taste and olfactory disorders. Analyzing retrospective cohort data from TriNetX and over 33 million records (Jan 2020-Dec 2022), this study focused on 1,512,358 participants, revealing that SUD significantly heightens the likelihood of experiencing taste disturbances and anosmia in Long-COVID sufferers. Results indicated that individuals with SUD face a higher incidence of sensory impairments compared to controls, with older adults and women being particularly vulnerable. Smokers with SUD were found to have an increased risk of olfactory and taste dysfunctions. The findings underscore the importance of early screening, diagnosis, and interventions for Long-COVID patients with a history of SUD, suggesting a need for clinicians to monitor for depression and anxiety linked to sensory dysfunction for comprehensive care.

Giving a Voice to Patients With Smell Disorders Associated With COVID-19: Cross-Sectional Longitudinal Analysis Using Natural Language Processing of Self-Reports.

BACKGROUND: Smell disorders are commonly reported with COVID-19 infection. The smell-related issues associated with COVID-19 may be prolonged, even after the respiratory symptoms are resolved. These smell dysfunctions can range from anosmia (complete loss of smell) or hyposmia (reduced sense of smell) to parosmia (smells perceived differently) or phantosmia (smells perceived without an odor source being present). Similar to the difficulty that people experience when talking about their smell experiences, patients find it difficult to express or label the symptoms they experience, thereby complicating diagnosis. The complexity of these symptoms can be an additional burden for patients and health care providers and thus needs further investigation. OBJECTIVE: This study aims to explore the smell disorder concerns of patients and to provide an overview for each specific smell disorder by using the longitudinal survey conducted in 2020 by the Global Consortium for Chemosensory Research, an international research group that has been created ad hoc for studying chemosensory dysfunctions. We aimed to extend the existing knowledge on smell disorders related to COVID-19 by analyzing a large data set of self-reported descriptive comments by using methods from natural language processing. METHODS: We included self-reported data on the description of changes in smell provided by 1560 participants at 2 timepoints (second survey completed between 23 and 291 days). Text data from participants who still had smell disorders at the second timepoint (long-haulers) were compared with the text data of those who did not (non-long-haulers). Specifically, 3 aims were pursued in this study. The first aim was to classify smell disorders based on the participants' self-reports. The second aim was to classify the sentiment of each self-report by using a machine learning approach, and the third aim was to find particular food and nonfood keywords that were more salient among long-haulers than those among non-long-haulers. RESULTS: We found that parosmia (odds ratio [OR] 1.78, 95% CI 1.35-2.37; P<.001) as well as hyposmia (OR 1.74, 95% CI 1.34-2.26; P<.001) were more frequently reported in long-haulers than in non-long-haulers. Furthermore, a significant relationship was found between long-hauler status and sentiment of self-report (P<.001). Finally, we found specific keywords that were more typical for long-haulers than those for non-long-haulers, for example, fire, gas, wine, and vinegar. CONCLUSIONS: Our work shows consistent findings with those of previous studies, which indicate that self-reports, which can easily be extracted online, may offer valuable information to health care and understanding of smell disorders. At the same time, our study on self-reports provides new insights for future studies investigating smell disorders.