Correlation of olfactory dysfunction with lung involvement and severity of COVID-19.

BACKGROUND: Olfactory dysfunction (OD) is a significant symptom of COVID-19 and may be the earliest symptom, or it may sometimes be the only manifestation of the disease. AIMS: To investigate whether OD is correlated with chest computed tomography (CT) findings, blood test parameters, and disease severity in COVID-19 patients. METHODS: The files of COVID-19 patients were retrospectively reviewed, and the ones who had information about smelling status and CT were taken into consideration. A total of 180 patients were divided into two groups: the OD group consisted of 89 patients with self-reported OD, and the No-OD group consisted of 91 subjects who did not complain of OD. The two groups were compared for the amount of lung consolidation on CT, intensive care unit (ICU) admission, and blood test parameters (complete blood count, alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatine kinase (CK), lactate dehydrogenase (LDH), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), ferritin, D-dimer, interleukin-6 (IL-6)). RESULTS: The amount of lung consolidation and ICU admission were significantly higher in the No-OD group (p < 0.001 for both). White blood cell (p = 0.06), monocyte (p = 0.26), and platelet (p = 0.13) counts and hemoglobin (p = 0.63), ALT (p = 0.89), and D-dimer (p = 0.45) levels of the two groups were similar. Lymphocyte count (p = 0.01), neutrophil count (p = 0.01), and AST (p = 0.03), CK (p = 0.01), LDH (p < 0.001), CRP (p < 0.001), ESR (p < 0.001), ferritin (p < 0.001), and IL-6 (p < 0.001) levels were significantly higher in the No-OD group. CONCLUSIONS: The patients presenting to the hospital with self-reported OD may have less lung involvement and a milder disease course compared to patients without OD on admission.

PHEV infection: A promising model of betacoronavirus-associated neurological and olfactory dysfunction.

Porcine hemagglutinating encephalomyelitis virus (PHEV) is a highly neurotropic coronavirus belonging to the genus Betacoronavirus. Similar to pathogenic coronaviruses to which humans are susceptible, such as SARS-CoV-2, PHEV is transmitted primarily through respiratory droplets and close contact, entering the central nervous system (CNS) from the peripheral nerves at the site of initial infection. However, the neuroinvasion route of PHEV are poorly understood. Here, we found that BALB/c mice are susceptible to intranasal PHEV infection and showed distinct neurological manifestations. The behavioral study and histopathological examination revealed that PHEV attacks neurons in the CNS and causes significant smell and taste dysfunction in mice. By tracking neuroinvasion, we identified that PHEV invades the CNS via the olfactory nerve and trigeminal nerve located in the nasal cavity, and olfactory sensory neurons (OSNs) were susceptible to viral infection. Immunofluorescence staining and ultrastructural observations revealed that viral materials traveling along axons, suggesting axonal transport may engage in rapid viral transmission in the CNS. Moreover, viral replication in the olfactory system and CNS is associated with inflammatory and immune responses, tissue disorganization and dysfunction. Overall, we proposed that PHEV may serve as a potential prototype for elucidating the pathogenesis of coronavirus-associated neurological complications and olfactory and taste disorders.

Long COVID, audiovestibular symptoms and persistent chemosensory dysfunction: a systematic review of the current evidence.

Objective: The persistence of auditory, vestibular, olfactory, and gustatory dysfunction for an extended time after COVID-19 has been documented, which represents an emerging challenge of which ENT specialists must be aware. This systematic review aims to evaluate the prevalence of persistent audiovestibolar and olfactory/gustatory symptoms in patients with "long-COVID". Methods: The literature was systematically reviewed according to PRISMA guidelines; PubMed, Scopus and Google Scholar were screened by searching articles on audiovestibular symptoms and olfactory/gustatory dysfunction after SARS-CoV-2 infection. The keywords used were hearing loss, tinnitus, vertigo, smell disorders, parosmia, anosmia, hyposmia, dysgeusia combined with COVID-19 or SARS-CoV-2. Results: 1100 articles were identified. After removal of duplicates (382), 702 articles were excluded, and 16 were included in the systematic review. All articles included identified an association between SARS-CoV-2 infection and persistent hearing or chemosensory impairment. The studies were published over a period of 2 years, between 2019 and 2021. Conclusions: The likelihood of patients with persistent audiovestibular symptoms related to COVID-19 was different among the articles; however, olfactory and gustatory disturbances were more consistently reported. Studies with longer follow-up are required to fully evaluate the long-term impact of these conditions.

Evaluation of olfactory dysfunction persistence after COVID-19: a prospective study.

OBJECTIVE: Alterations of the olfactory function in patients affected by COVID-19 often have an early onset and a variable duration ranging from a few weeks to months. The aim of this study was to evaluate olfactory dysfunction persistence after recovery from COVID-19, and potential related clinical-demographic conditions. PATIENTS AND METHODS: A total of 76 patients recovered from COVID-19 from at least 20 days with olfactory dysfunction during the infection were included in the study. For the subjective evaluation of olfactory function, a visual analogic scale (VAS) was used. The objective evaluation was performed with the use of the Sniffin' Sticks test. RESULTS: Objective assessment of olfactory function revealed that 48 (63.16%) patients were found to be normosmic (TDI ≥ 30.5), 26 (34.21%) were hyposmic (TDI from 30.5 to 16.5) and two (2.63%) were anosmic (TDI ≤ 16.5) at the time of the evaluation. These results did not show a significant difference between subjective and objective tests (p = 0.45). Most patients recovered their sense of smell within the first two months after recovery while a portion (22.2%) still experienced olfactory alterations 4-6 months after SARS-CoV-2 infection. Patients who had not recovered their sense of smell had a significantly longer period of SARS-CoV-2 positivity compared to patients that fully recovered (36.07 ± 7.78 days vs. 29 ± 7.89 days; p = 0.04). CONCLUSIONS: Our results suggest that the duration of the infection negatively correlates with the recovery of olfactory function.

Development and Validation of a Novel At-home Smell Assessment.

IMPORTANCE: Current tools for diagnosis of olfactory dysfunction (OD) are costly, time-consuming, and often require clinician administration. OBJECTIVE: To develop and validate a simple screening assessment for OD using common household items. DESIGN, SETTING, AND PARTICIPANTS: This fully virtual diagnostic study included adults with self-reported OD from any cause throughout the US. Data were collected from December 2020 to April 2021 and analyzed from May 2021 to July 2021. MAIN OUTCOMES AND MEASURES: Participants with self-reported olfactory dysfunction took a survey assessing smell perception of 45 household items and completed the Clinical Global Impression-Severity (CGI-S) smell questionnaire, the University of Pennsylvania Smell Identification Test (UPSIT), and the 36-item Short Form Survey (SF-36). Psychometric and clinimetric analyses were used to consolidate 45 household items into 2 short Novel Anosmia Screening at Leisure (NASAL) assessments, NASAL-7 (range, 0-14; lower score indicating greater anosmia) and NASAL-3 (range, 0-6; lower score indicating greater anosmia). RESULTS: A total of 115 participants were included in the study, with a median (range) age of 42 (19-70) years, 92 (80%) women, and 97 (84%) White individuals. There was a moderate correlation between the UPSIT and NASAL-7 scores and NASAL-3 scores (NASAL-7: ρ = 0.484; NASAL-3: ρ = 0.404). Both NASAL-7 and NASAL-3 had moderate accuracy in identifying participants with anosmia as defined by UPSIT (NASAL-7 area under the receiver operating curve [AUC], 0.706; 95% CI, 0.551-0.862; NASAL-3 AUC, 0.658; 95% CI, 0.503-0.814). Scoring 7 or less on the NASAL-7 had 70% (95% CI, 48%-86%) sensitivity and 53% (95% CI, 43%-63%) specificity in discriminating participants with anosmia from participants without. Scoring 2 or less on the NASAL-3 had 57% (95% CI, 36%-76%) sensitivity and 78% (95% CI, 69%-85%) specificity in discriminating participants with anosmia from participants without. There was moderate agreement between UPSIT-defined OD categories and those defined by NASAL-7 (weighted κ = 0.496; 95% CI, 0.343-0.649) and those defined by NASAL-3 (weighted κ = 0.365; 95% CI, 0.187-0.543). The agreement with self-reported severity of olfactory dysfunction as measured by CGI-S and the NASAL-7 and NASAL-3 was moderate, with a weighted κ of 0.590 (95% CI, 0.474-0.707) for the NASAL-7 and 0.597 (95% CI, 0.481-0.712) for the NASAL-3. CONCLUSION AND RELEVANCE: The findings of this diagnostic study suggest that NASAL-7 and NASAL-3, inexpensive and brief patient-reported assessments, can be used to identify individuals with OD. As the burden of COVID-19-associated OD increases, these assessments may prove beneficial as screening and diagnostic tools. Future work will explore whether the NASAL assessments are sensitive to change and how much of a change is clinically important.

Frequency of olfactory dysfunction in pregnant women with SARS-CoV-2 infection.

INTRODUCTION: In patients with COVID-19, olfactory dysfunction and anosmia have been reported, which in pregnant women occur in up to 24.2 %. OBJECTIVE: To know the frequency at which pregnant women with SARS-CoV-2 infection have olfactory dysfunction. METHODS: Age, gestational age, temperature, presence of nasal constipation or rhinorrhea, myalgia, headache, cough or chest pain were asked. Whether patients perceived and identified the scent of grape juice, coffee powder and menthol was evaluated. Central tendency and dispersion measures, frequencies and percentages were used. Sensitivity, specificity, positive and negative predictive value were calculated. Mann-Whitney's U-test and contrast of proportions were used for comparisons between groups. RESULTS: There was a higher proportion of women with cough, headache, dyspnea, myalgia, odynophagia, rhinorrhea, chest pain, and anosmia in SARS-CoV-2-positive women. In patients without COVID-19, 88.9 % detected each one of the scents; only 31.8 % of the positive group detected grapes scent, 47.7 % coffee and 59.1 % menthol, which had the highest percentages of sensitivity (40 %), specificity (21 %), positive predictive value (59 %) and negative predictive value (11 %). CONCLUSION: Olfactory dysfunction occurs in a significant percentage of pregnant women with COVID-19.

INTRODUCCIÓN: En pacientes con COVID-19 se ha reportado disfunción olfatoria y anosmia; en la mujer embarazada se presenta hasta en 24.2 %. OBJETIVO: Conocer la frecuencia con la que las mujeres embarazadas e infección por SARS-CoV-2 tienen disfunción olfatoria. MÉTODOS: Se preguntó edad, edad gestacional, temperatura, presencia de constipación nasal o rinorrea, mialgias, cefalea, tos o dolor torácico, además de evaluar si las mujeres percibían e identificaban el aroma de jugo de uva, café en polvo y mentol. Se utilizaron medidas de tendencia central y dispersión, frecuencias y porcentajes. Se calculó sensibilidad, especificidad, valor predictivo positivo y negativo. La U de Mann-Whitney y el contraste de proporciones sirvieron para las comparaciones entre los grupos. RESULTADOS: Hubo mayor proporción de mujeres con tos, cefalea, disnea, mialgias, odinofagia, rinorrea, dolor torácico y anosmia en mujeres positivas a SARS-CoV-2. De las pacientes sin COVID-19, 88.9 % detectó cada uno de los aromas; solo 31.8 % del grupo positivo detectó el aroma a uva, 47.7 % el de café y 59.1 % el de mentol, el cual tuvo los porcentajes más altos en sensibilidad (40 %), especificidad (21 %), valores predictivos positivo (59 %) y negativo (11 %). CONCLUSIÓN: la disfunción olfatoria se presenta en un porcentaje importante de las mujeres embarazadas con COVID-19.

Post-viral effects of COVID-19 in the olfactory system and their implications.

BACKGROUND: The mechanisms by which any upper respiratory virus, including SARS-CoV-2, impairs chemosensory function are not known. COVID-19 is frequently associated with olfactory dysfunction after viral infection, which provides a research opportunity to evaluate the natural course of this neurological finding. Clinical trials and prospective and histological studies of new-onset post-viral olfactory dysfunction have been limited by small sample sizes and a paucity of advanced neuroimaging data and neuropathological samples. Although data from neuropathological specimens are now available, neuroimaging of the olfactory system during the acute phase of infection is still rare due to infection control concerns and critical illness and represents a substantial gap in knowledge. RECENT DEVELOPMENTS: The active replication of SARS-CoV-2 within the brain parenchyma (ie, in neurons and glia) has not been proven. Nevertheless, post-viral olfactory dysfunction can be viewed as a focal neurological deficit in patients with COVID-19. Evidence is also sparse for a direct causal relation between SARS-CoV-2 infection and abnormal brain findings at autopsy, and for trans-synaptic spread of the virus from the olfactory epithelium to the olfactory bulb. Taken together, clinical, radiological, histological, ultrastructural, and molecular data implicate inflammation, with or without infection, in either the olfactory epithelium, the olfactory bulb, or both. This inflammation leads to persistent olfactory deficits in a subset of people who have recovered from COVID-19. Neuroimaging has revealed localised inflammation in intracranial olfactory structures. To date, histopathological, ultrastructural, and molecular evidence does not suggest that SARS-CoV-2 is an obligate neuropathogen. WHERE NEXT?: The prevalence of CNS and olfactory bulb pathosis in patients with COVID-19 is not known. We postulate that, in people who have recovered from COVID-19, a chronic, recrudescent, or permanent olfactory deficit could be prognostic for an increased likelihood of neurological sequelae or neurodegenerative disorders in the long term. An inflammatory stimulus from the nasal olfactory epithelium to the olfactory bulbs and connected brain regions might accelerate pathological processes and symptomatic progression of neurodegenerative disease. Persistent olfactory impairment with or without perceptual distortions (ie, parosmias or phantosmias) after SARS-CoV-2 infection could, therefore, serve as a marker to identify people with an increased long-term risk of neurological disease.

Olfactory dysfunction and coronavirus disease 2019 severity: a prospective cohort study.

OBJECTIVE: The primary goal of this study was to evaluate the association between olfactory dysfunction or taste impairment and disease severity and radiological findings in coronavirus disease-2019. The secondary goal was to assess the prevalence, severity and course of olfactory dysfunction or taste impairment in patients with coronavirus disease 2019. METHOD: This prospective observational cohort study evaluated patients hospitalised with coronavirus disease 2019 between April 1 and 1 May 2020. Olfactory dysfunction and taste impairment were evaluated by two questionnaires. Chest computed tomography findings and coronavirus disease-2019 severity were assessed. RESULTS: Among 133 patients, 23.3 per cent and 30.8 per cent experienced olfactory dysfunction and taste impairment, respectively, and 17.2 per cent experienced both. The mean age was 56.03 years, and 64.7 per cent were male and 35.3 per cent were female. No statistically significant association was found between olfactory dysfunction (p = 0.706) and taste impairment (p = 0.35) with either disease severity or chest computed tomography grading. CONCLUSION: Olfactory dysfunction or taste impairment does not have prognostic importance in patients with coronavirus disease 2019.

Impact of olfactory dysfunction on quality of life in coronavirus disease 2019 patients: a systematic review.

OBJECTIVE: To outline the impact on quality of life in coronavirus disease 2019 patients with olfactory dysfunction. METHODS: Five databases were searched for articles referring to the impact on quality of life in coronavirus disease 2019 patients with olfactory dysfunction. The search was conducted for the period from November 2019 to April 2021. The search was conducted over one month (May 2021). RESULTS: Four studies that met the objective were included. Altogether, there were 1045 patients. Various questionnaires were used to assess quality of life. Overall, the quality of life deficit affected 67.7 per cent of patients. Quality of life domains investigated include overall quality of life (four studies), food and taste dysfunction (two studies), mental health (two studies), cognitive function (one study), functional outcome (one study) and safety domains (one study). CONCLUSION: Quality of life deficit was reported to be 67.7 per cent among coronavirus disease 2019 patients with olfactory dysfunction. The high prevalence of persistent olfactory dysfunction prompts more serious research, as the long-standing consequences of olfactory dysfunction are detrimental.

Clinical Features of Parosmia Associated With COVID-19 Infection.

OBJECTIVE: To characterize the clinical features, risk factors, symptom time-course, and quality of life implications for parosmia among coronavirus disease (COVID)-related olfactory dysfunction patients. METHODS: Individuals with olfactory dysfunction associated with laboratory-confirmed or clinically suspected COVID-19 infection were recruited from otolaryngology and primary care practices over a period from August 2020 to March 2021. Participants completed olfactory dysfunction and quality of life surveys. RESULTS: A total of 148 (64.1%) of 231 respondents reported parosmia at some point. Parosmia developed within 1 week of any COVID-19 symptom onset in 25.4% of respondents, but more than 1 month after symptom onset in 43.4% of respondents. Parosmia was associated with significantly better quantitative olfactory scores on Brief Smell Identification Test (8.7 vs. 7.5, P = .006), but demonstrated worse quality of life scores, including modified brief Questionnaire of Olfactory Dysfunction-Negative Statements and Sino-Nasal Outcome Test-22 scores (12.1 vs. 8.5, P < .001; 26.2 vs. 23.2, P = .113). Participants who developed parosmia at any point were significantly younger and less likely to have history of chronic sinusitis than those who did not develop parosmia (40.2 vs. 44.9 years, P = .007; 7.2% vs. 0.7%, P = .006). CONCLUSION: COVID-19-associated olfactory dysfunction is frequently linked with development of parosmia, which often presents either at onset of smell loss or in a delayed fashion. Despite better quantitative olfactory scores, respondents with parosmia report decreased quality of life. A majority of respondents with persistent parosmia have sought treatment. LEVEL OF EVIDENCE: 3 Laryngoscope, 132:633-639, 2022.

Olfactory recovery following infection with COVID-19: A systematic review.

Olfactory loss has been identified as one of the common symptoms related to COVID-19 infection. Although olfactory loss is recognized, our understanding of both the extent of loss and time to olfactory recovery following infection is less well known. Similarly, knowledge of potential impactful patient factors and therapies that influence olfactory recovery is desirable but is not overtly clear in the literature. Our systematic review sought to fill this knowledge gap. We included studies that: involved either an observational or an interventional design that reported data on patients with olfactory dysfunction due to Reverse Transcription Polymerase Chain Reaction (RT-PCR) diagnosed COVID-19 infection; and reported data regarding olfactory recovery measured by an objective olfactory test, Likert scale and/or visual analog scale (VAS). The study methods were determined a priori and registered in PROSPERO (Registration Number CRD42020204354). An information specialist searched Medline, Embase, LitCovid and the Cochrane Register of Controlled Trials up to March 2021, and two reviewers were involved in all aspects of study selection and data collection. After screening 2788 citations, a total of 44 studies of assorted observational designs were included. Patients had undergone objective COVID-19 testing, and most were adult patients with mild to moderate COVID-19. Olfactory recovery was found to occur as early as 7 days, with most patients recovering olfaction within 30 days. Few studies included prolonged follow-up to 6 months or longer duration. Poor olfaction at initial presentation was associated with poor recovery rates. Only a small number of studies assessed olfactory retraining and steroid therapy. Additional trials are underway.

Patterns and clinical outcomes of olfactory and gustatory disorders in six months: Prospective study of 1031 COVID-19 patients.

OBJECTIVE: This study aims to comprehensively evaluate olfactory and gustatory dysfunctions during the COVID-19 pandemic regarding onset, course, associated symptoms, prognosis and relation to patients' demographics, treatment received and other symptoms. PATIENTS& METHODS: This is a prospective study conducted on patients proven to be infected with COVID-19 and with olfactory/gustatory dysfunction symptoms. Detailed history was taken from each patient about the onset of this dysfunction, associated symptoms. Then follow-up survey was done after 6 months to evaluate the prognosis. RESULTS: 1031 patients were included in the study, aged 18 to 69 years old, with 31.8% were male. Olfactory/gustatory dysfunctions occurred after other COVID-19 symptoms in 43.5% of cases, occurred suddenly in 80.4% and gradually in 19.6%. These dysfunctions were anosmia & ageusia in 50.2%, hyposmia & hypogeusia in 23.3%, anosmia alone in 17.7%, phantosmia in 18%, Parosmia in 28.4%. In terms of recovery 6-month follow up, 680 patients (66%) recovered completely, 22.1% recovered partially while 11.9% did not recover. Most improvement occurred in the first two weeks. Headache, malaise, nasal obstruction and rhinorrhea were the commonest COVID-19 symptoms associated. CONCLUSION: Most recovery of olfactory/gustatory dysfunction in COVID-19 infection occurs at the first two weeks and is unrelated to patient demographics, treatment or olfactory training. Parosmia is an independent predictor for complete recovery, while phantosmia is significantly associated with lower probability of complete recovery.

Prevalence of Symptoms More Than Seven Months After Diagnosis of Symptomatic COVID-19 in an Outpatient Setting.

BACKGROUND: With millions of SARS-CoV-2 infections worldwide, increasing numbers of patients are coming forward with long-term clinical effects of the disease lasting several weeks to months. OBJECTIVE: To characterize symptoms 7 to 9 months after diagnosis of COVID-19. DESIGN: Self-reported surveys and semistructured telephone interviews at enrollment and 30 to 45 days and 7 to 9 months from diagnosis. SETTING: From 18 March to 15 May 2020, symptomatic persons who tested positive for SARS-CoV-2 at the Geneva University Hospitals were followed by CoviCare, a virtual, clinical, outpatient follow-up program. Persons were contacted again at 30 to 45 days and 7 to 9 months from diagnosis. PARTICIPANTS: Persons who were a part of the CoviCare program from 18 March to 15 May 2020. MEASUREMENTS: A standardized interview of symptoms consistent with COVID-19, with grading of intensity. RESULTS: Of the 629 participants in the study who completed the baseline interviews, 410 completed follow-up at 7 to 9 months after COVID-19 diagnosis; 39.0% reported residual symptoms. Fatigue (20.7%) was the most common symptom reported, followed by loss of taste or smell (16.8%), dyspnea (11.7%), and headache (10.0%). LIMITATION: Limitations include generalizability and missing data for 34.8% of participants. CONCLUSION: Residual symptoms after SARS-CoV-2 infection are common among otherwise young and healthy persons followed in an outpatient setting. These findings contribute to the recognition of long-term effects in a disease mostly counted by its death toll to date by promoting communication on postacute sequelae of SARS-CoV-2 and encouraging physicians to continue long-term monitoring of their patients. PRIMARY FUNDING SOURCE: None.

Predictors of smell recovery in a nationwide prospective cohort of patients with COVID-19.

OBJECTIVE: To determine which factors (demographic, symptoms, comorbidities, and treatments) are associated with recovery of smell in patients with COVID-19 associated olfactory loss. STUDY DESIGN: Prospective, longitudinal questionnaires. SETTING: National survey. METHODS: A longitudinal web-based nationwide survey of adults with COVID-19 associated smell and taste loss was launched April 10, 2020. After completing an initial entry survey, participants received detailed follow-up questionnaires 14 days, and 1, 3 and 6 months later. RESULTS: As of June 25, 2021, 798 participants met study inclusion criteria and completed 6-month questionnaires. Of demographic characteristics only age <40 years was positively associated with smell recovery (p < .003). Of symptoms, difficulty breathing was negatively associated with smell recovery (p < .004), and nasal congestion positively associated with smell recovery (p < .03). Of pre-existing comorbidities only previous head injury (p < .017) was negatively associated with smell recovery. None of the queried medications used to treat COVID were associated with better rates of smell recovery. CONCLUSIONS: Age <40 and presence of nasal congestion at time of COVID-19 infection were predictive of improved rates of smell recovery, while difficulty breathing at time of COVID-19 infection, and prior head trauma predicted worsened rates of recovery. Further study will be required to identify potential mechanisms for the other observed associations. Such information can be used by clinicians to counsel patients suffering COVID-19 associated smell loss as to prognosis for recovery.

Olfactory dysfunction amongst children and adolescents with laboratory confirmed coronavirus disease 2019: a systematic review.

BACKGROUND: Despite the rapidly emerging reports of olfactory dysfunction amongst adult patients with coronavirus disease 2019, cases involving children and adolescents are scarcely reported. The literature was reviewed to elucidate olfactory dysfunction amongst children and adolescents with coronavirus disease 2019. METHODS: A search of the literature published from 1 December 2019 to 30 April 2021 was conducted using four databases, based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. The search was performed over one month (May 2021). RESULTS: Only 9 articles were identified, with a total of 316 laboratory confirmed coronavirus disease 2019 positive children and adolescents, of whom 156 reported olfactory dysfunction. Four studies reported olfactory dysfunction based on subjective tests; four studies carried out objective assessment. Most studies reported on olfaction recovery. CONCLUSION: The literature review revealed an olfactory dysfunction rate of 49 per cent amongst children and adolescents with coronavirus disease 2019. Persistence of olfactory dysfunction was reported in 7.1 per cent of the patients. Further studies involving objective measures need to be carried out in children and adolescents with coronavirus disease 2019.

Patients with COVID-19-associated olfactory impairment also show impaired trigeminal function.

OBJECTIVE: Next to olfactory function, the nose can also perceive chemestetic sensations mediated by the trigeminal nerve. While olfactory dysfunction as a symptom of COVID-19 is well described, there has been little research on the limitation of other nasal sensory inputs due to SARS-CoV-2 infection. The aim of this study was to determine possible limitations of nasal chemesthesis after COVID-19 infection by a psychophysiological diagnostic tool. METHODS: In 65 patients with a PCR-confirmed, former COVID-19 disease, olfaction was tested by means of a sniffin' sticks test, tasting by taste sprays and chemesthesis with a menthol dilution series. The subjective self-assessment of the patients was recorded via a questionnaire. RESULTS: We found a restriction of nasal chemesthesis and the extent correlated with the loss of smell, as well as with the values of the taste score, but not with subjective self-assessment. CONCLUSION: Not only the ability to smell and taste, but also nasal chemesthesis is affected by COVID-19.