Effectiveness of platelet-rich plasma in long-lasting post-viral olfactory dysfunction: a case-series.

OBJECTIVE: To investigate the platelet-rich plasma (PRP) effectiveness in patients with a long-lasting postviral olfactory dysfunction (LPOD). METHODS: Forty-three consecutive patients with a long-lasting postviral OD were prospectively recruited. The injection of 1 mL of PRP was carried out in both olfactory clefts. The pre- to 6-month post-PRP injection change in olfaction was assessed with the olfactory disorder questionnaire (ODQ) and the threshold, discrimination, and identification (TDI) tests. RESULTS: Forty-three patients received bilateral PRP injections (24 females). The mean age of patients was 58.9 ± 16.8 years. The mean duration of LPOD was 8.7 years. The pre to 6-month post-injection mean TDI significantly improved from 10.3 ± 10.2 to 20.12 ± 12.07 (p = 0.001). The mean ODQ significantly decreased from 29.8 ± 13.0 to 23.4 ± 11.3 (p = 0.013). The average change of the TDI and the ODQ were 9.8 and 6.4, respectively. Age was inversely associated with the 6-month threshold score. CONCLUSION: PRP appears to be a promising therapeutic strategy for long-lasting postviral OD. Our findings support the conduction of controlled randomized trial in this population of patients.

The long-term effect of COVID-19 infection on olfaction and taste; a prospective analysis.

PURPOSE: To estimate long-term prognosis of chemosensory dysfunctions among patients recovering from COVID-19 disease. METHODS: Between April 2020 and July 2022, we conducted a prospective, observational study enrolling 48 patients who experienced smell and/or taste dysfunction during the acute-phase of COVID-19. Patients were evaluated for chemosensory function up to 24 months after disease onset. RESULTS: During the acute-phase of COVID-19, 80% of patients reported anosmia, 15% hyposmia, 63% ageusia, and 33% hypogeusia. At two years' follow-up, 53% still experienced smell impairment, and 42% suffered from taste impairment. Moreover, 63% of patients who reported parosmia remained with olfactory disturbance. Interestingly, we found a negative correlation between visual analogue scale scores for smell and taste impairments during the acute-phase of COVID-19 and the likelihood of long-term recovery. CONCLUSION: Our study sheds light on the natural history and long-term follow-up of chemosensory dysfunction in patients recovering from COVID-19 disease. Most patients who initially suffered from smell and/or taste disturbance did not reach full recovery after 2 years follow-up. The severity of impairment may serve as a prognostic indicator for full recovery.

Inflammatory Response and Defects on Myelin Integrity in the Olfactory System of K18hACE2 Mice Infected with SARS-CoV-2.

Viruses, such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), use respiratory epithelial cells as an entry point for infection. Within the nasal cavity, the olfactory epithelium (OE) is particularly sensitive to infections which may lead to olfactory dysfunction. In patients suffering from coronavirus disease 2019, deficits in olfaction have been characterized as a distinctive symptom. Here, we used the K18hACE2 mice to study the spread of SARS-CoV-2 infection and inflammation in the olfactory system (OS) after 7 d of infection. In the OE, we found that SARS-CoV-2 selectively targeted the supporting/sustentacular cells (SCs) and macrophages from the lamina propria. In the brain, SARS-CoV-2 infected some microglial cells in the olfactory bulb (OB), and there was a widespread infection of projection neurons in the OB, piriform cortex (PC), and tubular striatum (TuS). Inflammation, indicated by both elevated numbers and morphologically activated IBA1+ cells (monocyte/macrophage lineages), was preferentially increased in the OE septum, while it was homogeneously distributed throughout the layers of the OB, PC, and TuS. Myelinated OS axonal tracts, the lateral olfactory tract, and the anterior commissure, exhibited decreased levels of 2',3'-cyclic-nucleotide 3'-phosphodiesterase, indicative of myelin defects. Collectively, our work supports the hypothesis that SARS-CoV-2 infected SC and macrophages in the OE and, centrally, microglia and subpopulations of OS neurons. The observed inflammation throughout the OS areas and central myelin defects may account for the long-lasting olfactory deficit.

Assessment of olfactory recovery after COVID-19: cross-sectional study.

OBJECTIVE: This study aimed to evaluate recovery patterns of olfactory dysfunction among recovered COVID-19 patients, both subjective and objective, and correlate this recovery to the severity of the disease. METHODS: The study recruited 200 patients and assigned them to two equal groups, one of them was a control group. The olfactory function of the study group was assessed via subjective and objective methods at baseline and then monthly for three months, with changes in smell function reported at each visit. These patients underwent chemosensory testing using the Sniffin' Sticks test and completed the validated Arabic version of the Questionnaire of Olfactory Disorders-Negative Statements (QOD-NS). RESULTS: Olfactory dysfunction occurred on the first day of COVID-19 symptoms in 37% of participants. Subjective reports suggested smell recovery in 55% after 3 months, but Sniffin' Sticks showed only 1% with normal function, indicating persistent deficits in others. This study revealed smell recovery for 93% of participants (median 14 days), with most (58%) recovering within 2 weeks. No significant links were found between demographics, COVID-smell loss timing, and recovery speed. CONCLUSION: Three months after COVID-19, many patients perceive smell recovery, but objective tests reveal shockingly high rates of persistent dysfunction. Further follow-up with objective tests is vital to assess the true burden and potential long-term effects of smell loss.

Therapeutic Efficacy of Nasal Corticosteroids in COVID-19-Related Olfactory Dysfunction: A Comprehensive Systematic Review and Meta-analysis.

OBJECTIVE: Olfactory disturbance is one of the main symptoms of coronavirus disease-2019 (COVID-19). Various olfactory disorders caused by viral infections are treated with nasal corticosteroids. This study aimed to evaluate the safety and efficacy of nasal corticosteroids in the treatment of olfactory disorders caused by the severe acute respiratory syndrome coronavirus 2. DATA SOURCES: We searched the Web of Science, Embase, PubMed, and Cochrane Library databases for clinical trials of nasal corticosteroids for treating COVID-19 olfactory dysfunction. REVIEW METHODS: We assessed the effect of nasal corticosteroids on olfactory function in COVID-19-affected individuals using a Meta-analysis of published studies, considering the number of patients who fully recovered from olfactory dysfunction, olfactory scores following treatment, and olfactory recovery time. RESULTS: Seven studies involving 930 patients were analyzed. The Meta-analysis results revealed that the olfactory score of the experimental group was 1.40 points higher than that of the control group (standardized mean difference [MD]: 1.40, 95% confidence interval [95% CI]: 0.34-2.47, P < .00001). However, the differences in the outcomes of cure rate (risk ratio: 1.18, 95% CI: 0.89-1.69, P = .21) and recovery time (MD: -1.78, 95% CI: -7.36 to 3.81, P = .53) were not statistically significant. Only 1 study reported adverse effects of nasal steroid treatment, namely tension, anger, and stomach irritation. CONCLUSION: Although nasal steroid therapy does not result in significant adverse effects, it proves ineffective in the treatment of COVID-19 olfactory dysfunction.

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.

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.

Características y prevalencia de las alteraciones del olfato y el gusto en pacientes con infección por COVID-19 / Characteristics of smell and taste alteration in patients with COVID-19

Introducción: La identificación de los síntomas o sus combinaciones con un alto valor predictivo para la enfermedad, es una estrategia crucial para el control de las enfermedades transmisibles. Las alteraciones en el olfato y el gusto han surgido como síntomas de alta prevalencia y un confiable predictor temprano de la enfermedad. El objetivo de este estudio fue caracterizar la prevalencia de las alteraciones del gusto y del olfato en pacientes con antecedente de infección por SARS-CoV-2 en la población colombiana. Materiales y métodos: estudio descriptivo de corte transversal. Se realizó una encuesta telefónica y electrónica a pacientes adultos con antecedente de infección por SARS-CoV-2 confirmado por PCR. Resultados: se incluyeron 182 pacientes en el estudio. El 59% manifestó alteraciones del olfato y 54% alteraciones del gusto. De estos, el 77% y 82%, respectivamente, presentaron mejoría de sus síntomas. El 14% de los participantes percibió las alteraciones del olfato antes del inicio de otros síntomas de COVID-19. El 9% reportó que la alteración del olfato fue el único síntoma de la infección. Para el gusto, 8% informó que fue el primer síntoma de COVID-19, mientras que el 6% reportó que fue el único síntoma. Conclusiones: las alteraciones del gusto y del olfato son síntomas de alta prevalencia en pacientes con infección por COVID-19 y en algunos casos pueden ser el síntoma de presentación de la infección o el único síntoma de la infección

Introduction: Identifying symptoms or symptom combinations with a high predictive value for diagnosing a disease is a crucial strategy for controlling transmissible diseases. Smell and taste alterations have been identified as highly prevalent symptoms of COVID-19 and have been used as a reliable early predictor of the disease. The objective in this study was characterizing the prevalence of smell and taste alterations in patients with COVID-19 in the Colombian population. Materials and methods: Cross-sectional, descriptive study. A telephonic and electronic survey was applied to adult patients with SARS-CoV-2 infection confirmed by PCR. Results: 182 patients were included. 59% presented with smell alterations and 54% with taste symptoms. Among these patients, 77% and 82% respectively perceived symptomatic improvement. 14% of patients presented smell alterations before the onset of other COVID-19 symptoms. 9% reported smell alterations to be the only symptom of the disease. 8% of patients perceived taste alterations as a first symptom and 6% reported it to be the only symptom of the disease. Conclusion: Taste and smell alterations are highly prevalent symptoms in Colombian patients with Covid-19 and in some cases they can be the either the first or the only perceived symptoms of the disease.

Diagnóstico clínico y tratamiento de la disfunción olfatoria relacionada con COVID-19: revisión de la literatura / Clinical diagnosis and treatment of olfactory dysfunction related to COVID-19: A literature review

Introducción: la enfermedad por coronavirus 2019 (COVID-19) es una enfermedad pandémica, que ha causado más de seis millones de muertes en todo el mundo. El cuadro clínico de la infección puede variar en función de la gravedad de la enfermedad y suele incluir síntomas generales, otorrinolaringológicos y neurológicos. Objetivo: proporcionar una revisión narrativa de la literatura científica sobre el diagnóstico clínico y tratamiento de la disfunción olfatoria relacionada con COVID-19. Resultados: la disfunción olfatoria definida como la capacidad reducida o distorsionada de oler al inhalar (olfato ortonasal) o al comer (olfato retronasal), a menudo se informa en casos leves o incluso asintomáticos. La prevalencia de la disfunción olfatoria puede variar con respecto al entorno clínico, con tasas de pérdida total del olfato hasta del 70 % en pacientes con COVID-19 leve. Además, hasta la fecha existen pocos artículos que evalúen prospectivamente las tasas de recuperación de la disfunción olfatoria en pacientes con COVID-19. Conclusión: COVID-19 se asocia con disfunción olfatoria en diversos pacientes. Se requiere una investigación activa y colaborativa para delinear la historia natural y el manejo apropiado de la disfunción olfatoria en esta virulenta enfermedad. Mientras tanto, el diagnóstico y los tratamientos dirigidos como el entrenamiento olfatorio pueden ser útiles en la disfunción olfatoria relacionada con COVID-19.

Introduction: Coronavirus disease 2019 is a pandemic disease that has caused more than six million deaths worldwide. The clinical picture of the infection can vary depending on the severity of the disease and usually includes general, ENT and neurological symptoms. Objective: To provide a narrative review of the scientific literature on the clinical diagnosis and treatment of olfactory dysfunction related to coronavirus disease 2019. Results: Olfactory dysfunction defined as the reduced or distorted ability to smell when inhaling (orthonasal smell) or when eating (postnasal smell), is often reported in mild or even asymptomatic cases. The prevalence of olfactory dysfunction can vary with respect to the clinical setting, with rates of total loss of smell as high as 70% in patients with mild coronavirus disease 2019. In addition, to date there is a paucity of articles prospectively evaluating recovery rates of olfactory dysfunction in patients with coronavirus disease 2019. Conclusion: Coronavirus disease 2019 is associated with olfactory dysfunction in various patients. Active and collaborative research is required to delineate the natural history and appropriate management of olfactory dysfunction in this virulent disease. In the meantime, diagnosis and targeted treatments such as olfactory training may be helpful in olfactory dysfunction related to coronavirus disease 2019.

Virus load and incidence of olfactory, gustatory, respiratory, gastrointestinal disorders in COVID-19 patients: A retrospective cohort study.

OBJECTIVES: This study investigated the relationship between viral load and the incidence of olfactory and gustatory dysfunction (OD and GD), the incidence of respiratory and gastrointestinal symptoms and the recovery of OD and GD in COVID-19 patients. DESIGN: A retrospective cohort study. SETTING AND PARTICIPANTS: This study was conducted on 599 outpatients' cases in Golestan province between February and June 2020. MAIN OUTCOME MEASURES: The incidence, severity (complete or partial) and recovery time of OD and GD and their associations with cycle threshold (CT) values of SARS-CoV-2 polymerase chain reaction were assessed. RESULTS: The mean age of patients was 38.27 ± 13.62 years. The incidence of general symptoms included myalgia 70.1%, headache 51.8%, fever 47.7% and dyspnoea 21.4%. 41.9% of patients had gastrointestinal symptoms, including abdominal pain 26.5%, diarrhoea 25.2%, nausea 20.5% and vomiting 12.9%. 12.2% of patients had comorbidity. The trimester recovery rates of OD and GD were 93.94% and 94.74% respectively. The mean recovery time of OD and GD was 14.56 ± 13.37 and 13.8 ± 3.77 days respectively. The mean CT value in all patients was 27.45 ± 4.55. There were significant associations between the mean of CT value with headache (p = 0.04), GD (p = 0.002) and OD (p = 0.001). CONCLUSIONS: The finding of this study indicates a possible association between viral load with incidence of OD and GD in COVID-19 patient's cases and assures the recovery of OD/GD in these patients.

Frecuencia de disfunción olfatoria en mujeres embarazadas con infección por SARS-CoV-2 / Frequency of olfactory dysfunction in pregnant women with SARS-CoV-2 infection

Resumen 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.

Abstract 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 in 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.

Association of Olfactory Training With Neural Connectivity in Adults With Postviral Olfactory Dysfunction.

Importance: Viral upper respiratory tract infections are a major cause of olfactory loss. Olfactory training (OT) is a promising intervention for smell restoration; however, a mechanistic understanding of the changes in neural plasticity induced by OT is absent. Objective: To evaluate functional brain connectivity in adults with postviral olfactory dysfunction (PVOD) before and after OT using resting-state functional magnetic resonance imaging. Design, Setting, and Participants: This prospective cohort study, conducted from September 1, 2017, to November 30, 2019, recruited adults with clinically diagnosed or self-reported PVOD of 3 months or longer. Baseline olfaction was measured using the University of Pennsylvania Smell Identification Test (UPSIT) and the Sniffin' Sticks test. Analysis was performed between December 1, 2020, and July 1, 2020. Interventions: Participants completed 12 weeks of OT using 4 essential oils: rose, eucalyptus, lemon, and clove. The resting-state functional magnetic resonance imaging measurements were obtained before and after intervention. Main Outcome and Measures: The primary outcome measure was the change in functional brain connectivity before and after OT. Secondary outcome measures included changes in UPSIT and Sniffin' Sticks test scores, as well as patient-reported changes in treatment response as measured by subjective changes in smell and quality-of-life measures. Results: A total of 16 participants with PVOD (11 female [69%] and 14 White [88%]; mean [SD] age, 60.0 [10.5] years; median duration of smell loss, 12 months [range, 3-240 months]) and 20 control participants (15 [75%] female; 17 [85%] White; mean [SD] age, 55.0 [9.2] years; median UPSIT score, 37 [range, 34-39]) completed the study. At baseline, participants had increased connectivity within the visual cortex when compared with normosmic control participants, a connection that subsequently decreased after OT. Furthermore, 4 other network connectivity values were observed to change after OT, including an increase in connectivity between the left parietal occipital junction, a region of interest associated with olfactory processing, and the cerebellum. Conclusions and Relevance: The use of OT is associated with connectivity changes within the visual cortex. This case-control cohort study suggests that there is a visual connection to smell that has not been previously explored with OT and that further studies examining the efficacy of a bimodal visual and OT program are needed.

Self-reported Taste and Smell Disorders in Patients with COVID-19: Distinct Features in China.

Last December 2019, a cluster of viral pneumonia cases identified as coronavirus disease 2019 (COVID-19) was reported in Wuhan, China. We aimed to explore the frequencies of nasal symptoms in patients with COVID-19, including loss of smell and taste, as well as their presentation as the first symptom of the disease and their association with the severity of COVID-19. In this retrospective study, 1206 laboratory-confirmed COVID-19 patients were included and followed up by telephone one month after discharged from Tongji Hospital, Wuhan. Demographic data, laboratory values, comorbidities, symptoms, and numerical rating scale scores (0-10) of nasal symptoms were extracted from the hospital medical records, and confirmed or reevaluated by the telephone follow-up. From patients (n=1172) completing follow-up, 199 (17%) subjects had severe COVID-19 and 342 (29.2%) reported nasal symptoms. 20.6% COVID-19 patients had loss of taste (median score=6), while 11.4% had loss of smell (median score=5). Loss of taste scores, but not loss of smell scores, were significantly increased in severe vs. non-severe COVID-19 patients. Interleukin (IL)-6 and lactose dehydrogenase (LDH) serum levels were positively correlated with loss of taste scores. About 80% of COVID-19 patients recovered from smell and taste dysfunction in 2 weeks. In this cohort, only 1 out of 10 hospital admitted patients had loss of smell while 1 out of 5 reported loss of taste which was associated to severity of COVID-19. Most patients recovered smell and taste dysfunctions in 2 weeks.

Self-reported smell and taste alteration as the sole clinical manifestation of SARS-CoV-2 infection.

Chemosensory dysfunction has increasingly been reported in patients with coronavirus disease 2019 (COVID-19). Here, we document a case of a patient with taste and smell alterations as the only clinical manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In March 2020, a 36-year-old woman presented with self-reported hypogeusia/ageusia and hyposmia/anosmia in the absence of any respiratory symptom. The patient, who had no clinical and radiographic signs of sinusitis and was otherwise healthy, eventually had a positive test result for SARS-CoV-2. She did not develop any COVID-19-related symptoms throughout her 6-month follow up. Her self-reported chemosensory dysfunction lasted for 12 weeks. To the best of our knowledge, this is the first report that has accurately documented taste and smell alteration as the sole manifestation of COVID-19 in an otherwise healthy individual. Overall, analysis of current evidence supports the inclusion of gustatory and olfactory alterations as cardinal symptoms of COVID-19. Dentists' awareness of the diagnostic criteria for case definition of COVID-19 can facilitate early detection of the disease.

Diagnostic Value of Patient-Reported and Clinically Tested Olfactory Dysfunction in a Population Screened for COVID-19.

Importance: Recent studies have suggested that olfactory dysfunction and gustatory dysfunction are associated with coronavirus disease 2019 (COVID-19). However, olfaction has been evaluated solely on reported symptoms, after COVID-19 diagnosis, and in both mild and severe COVID-19 cases, but rarely has it been assessed in prospectively unselected populations. Objective: To evaluate the diagnostic value of a semiobjective olfactory test developed to assess patient-reported chemosensory dysfunction prior to testing for the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients attending a COVID-19 screening facility. Design, Setting, and Participants: This prospective diagnostic study with participants and observers blinded to COVID-19 status was conducted in a COVID-19 screening center of a tertiary university hospital in France from March 23 to April 22, 2020. Participants were 854 consecutively included health care workers or outpatients with symptoms or with close contact with an index case. Exclusion criteria were prior chemosensory dysfunction, testing inability, or contraindications (n = 45). Main Outcomes and Measures: Participants were interviewed to ascertain their symptoms and then underwent Clinical Olfactory Dysfunction Assessment (CODA), an ad hoc test developed for a simple and fast evaluation of olfactory function. This assessment followed a standardized procedure in which participants identified and rated the intensity of 3 scents (lavender, lemongrass, and mint) to achieve a summed score ranging from 0 to 6. The COVID-19 status was assessed using reverse transcriptase-polymerase chain reaction to detect the presence of SARS-CoV-2 in samples collected via nasopharyngeal swab (reference standard) to calculate the diagnostic values of patient-reported chemosensory dysfunction and CODA. Results: Of 809 participants, the female to male sex ratio was 2.8, and the mean (SD) age was 41.8 (13.0) years (range, 18-94 years). All participants, if symptomatic, had mild disease at the time of testing, and 58 (7.2%) tested positive for SARS-CoV-2. Chemosensory dysfunction was reported by 20 of 58 participants (34.5%) with confirmed COVID-19 vs 29 of 751 participants (3.9%) who tested negative for COVID-19 (absolute difference, 30.6% [95% CI, 18.3%-42.9%]). Olfactory dysfunction, either self-reported or clinically ascertained (CODA score ≤3), yielded similar sensitivity (0.31 [95% CI, 0.20-0.45] vs 0.34 [95% CI, 0.22-0.48]) and specificity (0.97 [95% CI, 0.96-0.98) vs 0.98 [95% CI, 0.96-0.99]) for COVID-19 diagnosis. Concordance was high between reported and clinically tested olfactory dysfunction, with a Gwet AC1 of 0.95 (95% CI, 0.93-0.97). Of 19 participants, 15 (78.9%) with both reported olfactory dysfunction and a CODA score of 3 or lower were confirmed to have COVID-19. The CODA score also revealed 5 of 19 participants (26.3%) with confirmed COVID-19 who had previously unperceived olfactory dysfunction. Conclusions and Relevance: In this prospective diagnostic study of outpatients with asymptomatic or mild to moderate COVID-19, systematically assessed anamnesis and clinical testing with the newly developed CODA were complementary and specific for chemosensory dysfunction. Olfactory dysfunction was suggestive of COVID-19, particularly when clinical testing confirmed anamnesis. However, normal olfaction was most common among patients with COVID-19.

Identification of Viruses in Patients With Postviral Olfactory Dysfunction by Multiplex Reverse-Transcription Polymerase Chain Reaction.

OBJECTIVES/HYPOTHESIS: To investigate causative viruses in patients with postviral olfactory disorders (PVOD). STUDY DESIGN: Case-control study. METHODS: One hundred fifty-one consecutive patients diagnosed with PVOD were enrolled, and samples from 38 patients who visited the doctor within 3 months of symptom onset were collected and analyzed. Thirty-two individuals who underwent surgery for nasal septal deviation during the same time period were collected as the control group. The Sniffin' Sticks psychophysical olfactory test was used to evaluate olfactory function. Olfactory cleft specimens were collected using nasopharyngeal flocked swabs (COPAN FLOQSwabs). Eighteen viruses were tested for with the Luminex xTAG RVP FAST v2 Assay Kit. RESULTS: Out of the 38 patients with PVOD, rhinoviruses were detected in 13 patients, and coronavirus OC43 was detected in one patient. The frequency of positive virus detection in the patients with anosmia was higher than in those with hyposmia (58.8% vs. 19.0%, P = 0.018). In control group, rhinovirus was identified in one patient (3.1%). Nasal obstruction was the most common symptom and was experienced by 71.0% of patients. CONCLUSIONS: Rhinovirus and coronavirus are more commonly identified in PVOD. Our methods represent an approach to screen for viruses that may be involved in PVOD. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:158-164, 2021.