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Olfactory dysfunction (OD) was one of the most common symptom of infection with the Wuhan strain of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) and could persist for several months after symptom onset. The pathogenesis of prolonged OD remains poorly understood but probably involves sustained viral replication associated with limited mucosal immune response to the virus. This prospective study was conducted to investigate the potential relationship between nasal SARS‐CoV‐2 viral load and antibody levels in patients with loss of smell. One hundred and five patients were recruited 2 weeks after presenting with confirmed coronavirus disease 2019 associated OD. Based on the identification sniffing test performed at enrollment, 52 patients were still anosmic or hyposmic and 53 were normosmic. SARS‐CoV‐2 was detectable in nasal wash of about 50% of anosmic and normosmic patients. Higher viral load was detected in anosmic patients with lower levels of SARS‐CoV‐2 specific nasal immunoglobulins (Ig) IgG and IgA. This association was not observed in normosmic patients. No relationship between nasal viral load and antibodies to endemic coronaviruses was observed. SARS‐CoV‐2 replication in the nasal cavity may be promoted by defective mucosal antibody responses in patients with OD. Boosting mucosal immunity may limit nasal SARS‐CoV‐2 replication and thereby help in the control of persistent OD. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the prevalence and the evolution of olfactory disorders (OD) related to coronavirus disease 2019 (COVID-19) in patients infected during the first and the second European waves. Methods: From March 2020 to October 2020, COVID-19 patients with OD were recruited and followed over the 12-month post-infection. The following data were collected: demographic, treatments, vaccination status, and olfactory function. Olfaction was assessed with the Olfactory Disorder Questionnaire (ODQ), and threshold, discrimination, and identification (TDI) test. Outcomes were compared between patients of the first wave (group 1: wild/D614G virus) and the second wave (group 2: B.1.1.7. Alpha variant) at 1-, 3- and 12-month post-infection. Results: Sixty patients completed the evaluations accounting for 33 and 27 patients in group 1 and 2, respectively. The 1-month TDI score (23.7 ± 5.3) was significantly lower in group 2 compared to group 1 (29.8 ± 8.7; p = 0.017). Proportion of normosmic patients at 1-month post-infection was significantly higher in group 1 compared to group 2 (p = 0.009). TDI scores only significantly increased from 1- to 3-month post-infection in anosmic and hyposmic patients. Focusing on There was a negative association between the 1-month ODQ and the 1-month TDI (rs = − 0.493; p = 0.012). ODQ was a significant predictor of TDI scores at 3- and 12-month post-infection. The 12-month prevalence of parosmia was 60.6% in group 1 and 42.4% in group 2, respectively. There was no significant influence of oral corticosteroid treatment, adherence to an olfactory training and vaccination status on the olfactory outcomes. Conclusions: Patients of the second wave (Alpha B.1.1.7. variant) reported significant higher proportion of psychophysical test abnormalities at 1-month post-infection than patients infected during the first wave (D614G virus). [ABSTRACT FROM AUTHOR]

Objective: To investigate safety, feasibility, and effectiveness of platelet-rich plasma (PRP) injection into the olfactory clefts of COVID-19 patients with persistent olfactory dysfunction (OD). Methods: From March 2022 to July 2022, COVID-19 patients with persistent OD were consecutively recruited to benefit from PRP injection into the olfactory clefts. Patient pain, annoyance, time of procedure, and adverse events were evaluated. Olfactory function was evaluated at baseline and 2-month post-injection with the olfactory disorder questionnaire (ODQ) and threshold, discrimination, and identification (TDI) test. Results: Eighty-seven patients with anosmia (N = 30), hyposmia (N = 40), or parosmia (N = 17) with a mean OD duration of 15.7 months completed the evaluations. The PRP injection was successfully performed in all patients with a mean procedure time of 18.4 ± 3.4 min. The adverse events included transient epistaxis (N = 31), parosmia related to xylocaine spray (N = 10), and vasovagal episode (N = 2). The injection procedure was evaluated as somewhat or moderately painful by 41 (47%) and 22 (25%) patients, respectively. Thirty-seven patients were assessed after 2 months post-injection. The mean ODQ and TDI scores significantly improved from baseline to 2-month post-injection (p < 0.01). The olfactory improvement occurred after a mean of 3.6 ± 1.9 weeks. Conclusion: The injection of PRP into the olfactory clefts is safe and associated with adequate patient-reported outcomes. The findings of this preliminary study suggest possible efficacy on subjective and psychophysical evaluations, but future randomized controlled studies are needed to determine the superiority of PRP injection over placebo. [ABSTRACT FROM AUTHOR]

Objectives: To investigate effectiveness of olfactory training (OT) in COVID-19 patients with persistent olfactory dysfunction (OD). Methods: From March 2020 to March 2022, COVID-19 patients with OD were prospectively followed in three European medical centers for a period of 18 months. A standardized OT protocol were recommended to patients. Patient-reported outcome questionnaires and psychophysical evaluations were used to evaluate olfaction at baseline, 6, 12, and 18 months after the start of OT. The evolution of olfactory outcome was compared according to the adherence to the OT protocol. Results: Fifty-seven patients completed the evaluations. Thirty-two patients fully adhered to the OT, while 25 did not adhere. The psychophysical scores significantly improved from baseline to 6-month post-infection in both groups. In the OT group, the psychophysical scores continued to significantly improve from 6 to 12 months after the start of OT (p = 0.032). The mean duration of OT was 15.4 weeks. The mean delay of patient recovery perception was comparable between groups (27.4 weeks). The occurrence of cacosmia (35.1%) and parosmia (43.9%) throughout the follow-up period was comparable between groups. There proportion of phantosmia was higher in training (34.4%) compared with no-OT (16.0%; p = 0.007) group. The baseline Sniffin'Sticks tests was positively associated with the 6-month Sniffin'Sticks tests (rs = 0.685; p < 0.001) and negatively associated with the time of recovery (rs = − 0.369; p = 0.034). Conclusions: The adherence to an OT protocol was associated with better mid-term improvement of psychophysical scores. Future large-cohort randomized-controlled studies are needed to confirm the effectiveness of OT in COVID-19 patients. [ABSTRACT FROM AUTHOR]

Objective: To investigate the prevalence and recovery of olfactory dysfunction (OD) in COVID‐19 patients 24 months after the infection. Methods: From 22 March 2020 to 5 June 2022, 251 COVID‐19 patients were followed in three European medical centres. Olfactory function was assessed with subjective patient‐reported outcome questionnaires and odour identification tests at baseline, 6, 12, 18 and 24 months postinfection. The predictive values of epidemiological and clinical data were investigated with multivariate analysis. Results: One hundred and seventy‐one patients completed the evaluations. The odour identification test revealed that 123 patients (50.8%) had OD at baseline. The prevalence of persistent psychophysical abnormalities at 6, 12, 18 and 24 months post‐COVID‐19 was 24.2%, 17.9%, 5.8% and 2.9%, respectively (p = 0.001). Parosmia occurred in 40 patients (23.4%) and lasted 60 ± 119 days. At 2 years, 51 patients (29.8%) self reported that their olfaction was unnormalised. Older patients had better odour identification evaluations at baseline (p < 0.001) but those with OD reported lower odour identification test scores at the end of the follow‐up. Parosmia occurred more frequently in young patients. The olfactory training was significantly associated with higher values of Sniffin' Sticks tests at 18 months postinfection (rs = 0.678; p < 0.001). Conclusion: Two years post‐COVID‐19, 29.8% of patients reported persistent OD, but only 2.9% had abnormal identification psychophysical evaluations. [ABSTRACT FROM AUTHOR]

Background: Interleukin 6 (IL-6) is a proinflammatory cytokine that is secreted by cells infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and it is widely recognized as a negative prognostic factor. The purpose of this study was to analyze the correlations between the olfactory scores determined by psychophysical tests and the serum levels of IL-6 in patients affected by coronavirus disease 2019 (COVID-19) Methods: Patients underwent psychophysical olfactory assessment with Connecticut Chemosensory Clinical Research Center test and IL-6 plasma level determination within 10 days of the clinical onset of COVID-19. Results: Seventy-four COVID-19 patients were included in this study. COVID-19 staged as mild in 34 patients, moderate in 26 and severe in 14 cases. There were no significant differences in olfactory scores across the different COVID-19 severity groups. In the patient series, the median plasma level of IL-6 was 7.7 pg/mL (IQR 3.7–18.8). The concentration of IL-6 was found to be significantly correlated with the severity of COVID-19 with a directly proportional relationship. The correlation between IL-6 plasma concentrations and olfactory scores was weak (rs = 0.182) and not significant (p = 0.12). Conclusions: In COVID-19 patients, psychophysical olfactory scores did not show significant correlations with the plasma levels of a well-recognized negative prognostic factor such as IL-6. This observation casts some shadows on the positive prognostic value of olfactory dysfunctions. [ABSTRACT FROM AUTHOR]

Background and purpose: The aim was to evaluate potential predictive factors of smell recovery in a clinical series of 288 patients presenting olfactory dysfunction (OD) related to coronavirus disease 2019 (COVID‐19). Potential correlations were sought between epidemiological, clinical and immunological characteristics of patients and the persistence of OD at 60 days. Methods: COVID‐19 positive patients presenting OD were prospectively recruited from three European hospitals. Baseline clinical and olfactory evaluations were performed within the first 2 weeks after OD onset and repeated at 30 and 60 days. In a subgroup of patients, anti‐severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) antibodies were measured in serum, saliva and nasal secretions at 60 days. Results: A total of 288 COVID‐19 patients with OD were included in the study. Two weeks after the onset of the loss of smell, 52.4% of patients had OD on psychophysical tests, including 113 cases (39.2%) of anosmia and 38 cases (13.2%) of hyposmia. At 60‐day follow‐up, 25.4% of the patients presented persistent OD. There was no significant correlation between sex, age, viral load on nasopharyngeal swab or COVID‐19 severity and poor olfactory outcome. In a subgroup of 63 patients, it was demonstrated that patients with poor olfactory outcomes at 60 days had lower levels of salivary and nasal immunoglobulin G (IgG) and IgG1, but similar levels of antibodies in the serum. Conclusions: No clinical markers predicted the evolution of OD at 60 days. Patients with poor olfactory outcome at 60 days had lower saliva and nasal antibodies, suggesting a role for local immune responses in the persistence of COVID‐19 related OD. [ABSTRACT FROM AUTHOR]

Chemosensitive dysfunctions are now considered as frequent and early symptoms of coronavirus disease 2019 (COVID-19). In the last few weeks, researchers' greatest efforts have been focusing mainly on the analysis of olfactory disorders, neglecting taste dysfunctions. According to our psychophysical evaluations, it can be inferred that the pathogenesis of taste disorders in COVID-19 patients is largely smell-independent. Moreover, isolated gustatory disorders are highly specific of SARS-CoV-2 infection. For these reasons, it is essential that gustatory dysfunctions, like olfactory disorders, are included in the COVID-19 guidelines. [ABSTRACT FROM AUTHOR]

Objective: To investigate prevalence and epidemiological and clinical factors associated with olfactory dysfunction (OD) and gustatory dysfunction (GD) in COVID-19 patients according to the disease severity. Study design: Cross-sectional study. Methods: A total of 2579 patients with a positive diagnosis of COVID-19 were identified between March 22 and June 3, 2020 from 18 European hospitals. Epidemiological and clinical data were extracted. Otolaryngological symptoms, including OD and GD, were collected through patient-reported outcome questionnaire and Sniffin'Sticks tests were carried out in a subset of patients. Results: A total of 2579 patients were included, including 2166 mild (84.0%), 144 moderate (5.6%) and 269 severe-to-critical (10.4%) patients. Mild patients presented an otolaryngological picture of the disease with OD, GD, nasal obstruction, rhinorrhea and sore throat as the most prevalent symptoms. The prevalence of subjective OD and GD was 73.7 and 46.8%, and decreases with the severity of the disease. Females had higher prevalence of subjective OD and GD compared with males. Diabetes was associated with a higher risk to develop GD. Among the subset of patients who benefited from psychophysical olfactory evaluations, there were 75 anosmic, 43 hyposmic and 113 normosmic patients. The prevalence of anosmia significantly decreased with the severity of the disease. Anosmia or hyposmia were not associated with any nasal disorder, according to SNOT-22. Conclusion: OD and GD are more prevalent in patients with mild COVID-19 compared with individuals with moderate, severe or critical diseases. Females might have a higher risk of developing OD and GD compared with males. [ABSTRACT FROM AUTHOR]

Background: From the start of the pandemic, many European otolaryngologists observed an unprecendented number of anosmic patients. Early reports proposed that anosmia could be the first or even the only symptom of COVID-19 infection, prompting calls for self-isolation in affected patients. Methods: In the present article, we review the COVID-19 anosmia literature and try to answer the following two questions: first, why is COVID-19 infection responsible for such a high incidence of anosmia? Second, in patients with more severe forms is anosmia really less prevalent and why? Results: In terms of the etiology of olfactory dysfunction, several hypotheses were proposed at the outset of the pandemic; that olfactory cleft inflammation and obstruction caused a localized conductive loss, that there was injury to the sustentacular supporting cells in the olfactory epithelium or, given the known neurotropic potential of coronavirus, that the virus could invade and damage the olfactory bulb. Olfactory cleft obstruction may contribute to the olfactory dysfunction in some patients, perhaps most likely in those that show very early resolution, it cannot account for the loss in all patients. Moreover, disordered regrowth and a predominance of immature neurons have been shown to be associated with parosmia, which is a common finding amongst patients with Covid-related anosmia. A central mechanism therefore certainly seems to be consistent with the group of patients with more prolonged olfactory deficits. Sustentacular cells showing ACE-2 immunohistochemical expression 200 to 700 times greater than nasal or tracheal epithelia seem to be the main SARS-CoV-2 gateway. As the pathophysiology of COVID-19 anosmia seems to be better understood, the question of why patients with a moderate to severe form of COVID-19 infection have less olfactory involvement remains unresolved. Different potential explanations are discussed in this review. Conclusions : The last 5 months have benefited from great international collaborative research, first highlighting and then proving the value of loss of smell and taste as a symptom of COVID-19. Adoption of loss of smell into the case definition by international public health bodies will facilitate control of disease transmission. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the clinical features of mild‐to‐moderate coronavirus disease 2019 (COVID‐19) in a sample of Italian patients and to investigate the occurrence of smell and taste disorders. Infected individuals with suspected (clinical diagnosis) or laboratory‐confirmed COVID‐19 infection were recruited. Patients completed a survey‐based questionnaire with the aim of assessing their epidemiological and clinical characteristics, general otorhinolaryngological symptoms, and smell and taste disorders. A total of 294 patients with mild‐to‐moderate COVID‐19 completed the survey (147 females). The most prevalent general symptoms included fever, myalgia, cough, and headache. A total of 70.4% and 59.2% of patients reported smell and taste disorders, respectively. A significant association between the two above‐mentioned disorders was found (rs: 0.412; P <.001). Smell disorders occurred before the other symptoms in 11.6% of patients and was not significantly associated with nasal obstruction or rhinorrhea. Interestingly, our statistical analysis did not show any significant difference, either for general symptoms or otorhinolaryngological features, between the clinical diagnosis group and the laboratory‐confirmed diagnosis (polymerase chain reaction) group. The structural equation model confirmed significant standardized paths (P <.05) between general symptoms, comorbidities, and general otorhinolaryngological complaints in the absence of a significant correlation between these elements and smell and taste alterations. The prevalence of smell and taste disorders in mild‐to‐moderate Italian COVID‐19 patients is significant both in suspected and laboratory‐confirmed cases and reveals a strong correlation between these clinical signs regardless of the presence of general or otorhinolaryngological symptoms, such as nasal obstruction or rhinorrhea. Highlights: This study evaluates the clinical features of mild‐to‐moderate COVID‐19 in a sample of adult Italian patients. The structural equation model (SEM) built to examine the clinical characteristics of the infection, confirms significant standardised paths between all the evaluated variables and underlines the absence of a significant correlation between smell and taste disorders and all the other variables. Furthermore, the study reveals a strong correlation between smell and taste alterations with a significant prevalence of these symptoms both in suspected (clinical diagnosis) and laboratory‐confirmed (pcr) cases. [ABSTRACT FROM AUTHOR]

Objective: COVID-19 patients may present mild symptoms. The identification of paucisymptomatic patients is paramount in order to interrupt the transmission chain of the virus. Olfactory loss could be one of those early symptoms which might help in the diagnosis of COVID-19 patients. In this study, we aim to develop and validate a fast, inexpensive, reliable and easy-to-perform olfactory test for the screening of suspected COVID-19 patients. Study design: Phase I was a case–control study and Phase II a transversal descriptive study. Subjects and methods: Olfaction was assessed with the ethyl alcohol threshold test and symptoms with visual analogue scales. The study was designed in two phases: In Phase I, we compared confirmed COVID-19 patients and healthy controls. In Phase II, patients with suspected COVID-19 infection referred for testing were studied. Results: 275 participants were included in Phase I, 135 in Phase II. The ROC curve showed an AUC of 0.749 in Phase I, 0.737 in Phase II. The cutoff value which offered the highest amount of correctly classified patients was ≥ 2 (10% alcohol) for all age intervals. The odds ratio was 8.19 in Phase I, 6.56 in Phase II with a 75% sensitivity. When cases report normal sense of smell (VAS < 4), it misdiagnoses 57.89% of patients detected by the alcohol threshold test. Conclusion: The olfactory loss assessed with the alcohol threshold test has shown high sensitivity and odds ratio in both patients with confirmed COVID-19 illness and participants with suspected SARS-CoV-2 infection. [ABSTRACT FROM AUTHOR]

The most reliable psychophysical test remains the threshold, discrimination, and identification (TDI), and the TDI results may provide substantial differences between the three components (T, D, and I) among COVID-19 patients [[8]]. Keywords: COVID-19; SARS-CoV-2; Olfaction; Smell; Otolaryngology; Head-neck surgery; Olfactory; Variant EN COVID-19 SARS-CoV-2 Olfaction Smell Otolaryngology Head-neck surgery Olfactory Variant 5469 5470 2 09/30/22 20221101 NES 221101 This comment refers to the article available online at https://doi.org/10.1007/s00405-022-07431-6. In this paper, Hintschich et al. investigated the olfactory dysfunction (OD) in COVID-19 patients according to the variant (alpha B.1.1.7. versus B.1617.2). [Extracted from the article]

(1) Background: Persistent olfactory (POD) and gustatory (PGD) dysfunctions are one of the most frequent symptoms of long-Coronavirus Disease 2019 but their effect on the quality of life (QoL) of patients is still largely unexplored. (2) Methods: An online survey was administered to individuals who reported to have had SARS-CoV-2 infection at least 6 months prior with persisting COVID-19 symptoms (using the COVID symptom index), including ratings of POD and PGD, and their physical (PCS) and mental (MCS) components of quality of life were assessed using the standardized short form 12 questionnaire (SF-12). (3) Results: Responses from 431 unique individuals were included in the analyses. The most frequent persistent symptoms were: fatigue (185 cases, 42.9%), olfactory dysfunction (127 cases, 29.5%), gustatory dysfunction (96 cases, 22.3%) and muscle pain (83 cases, 19.3%). Respondents who reported persisting muscle pain, joint pain, fatigue, headache, gastrointestinal disturbances, and dyspnea had significantly worse PCS. Those experiencing persistent fatigue and dyspnea also showed significantly lower MCS. Respondents reporting POD or PGD showed significantly worse QoL, but only pertaining to the MCS. Multiple regressions predicted MCS based on olfactory and marginally on gustatory ratings, but not PCS. Age significantly affected the prediction of PCS but not MCS, and gender and temporal distance from the COVID-19 diagnosis had no effect. (4) Conclusions: POD and PGD are frequent symptoms of the long-COVID-19 syndrome and significantly reduce QoL, specifically in the mental health component. This evidence should stimulate the establishment of appropriate infrastructure to support individuals with persistent CD, while research on effective therapies scales up. [ABSTRACT FROM AUTHOR]

Background: The objective of this study was to investigate the efficacy and safety of early administration of oral corticosteroids (OC) or nasal corticosteroids (NC) as an add-on to olfactory training (OT) versus OT alone in patients with olfactory dysfunction (OD) related to coronavirus disease 2019 (COVID-19). Methods: Patients with a positive diagnosis of COVID-19 and OD were prospectively recruited from March 22 to December 15, 2020 from 4 European hospitals. Patients had confirmed OD on psychophysical testing. All patients undertook OT, with add-on 10 days of OC (group 1: OC + OT), or 1 month of NC (group 2: NC + OT) or olfactory training alone (group 3: OT). Olfactory evaluations (Sniffin'Sticks tests) were carried out at the time of inclusion, 1 and 2 months after the start of the therapeutic course. Results: A total of 152 hyposmic or anosmic patients completed the study. Group 1, 2 and 3 included 59, 22 and 71 patients, respectively and all patient groups were comparable regarding baseline Sniffin'Sticks tests. The median Sniffin'Sticks test values significantly improved from pre- to post-intervention in all groups. The increase of Sniffin'Sticks test values was higher in group 1 (OC + OT) compared with groups 2 and 3 (p < 0.001) at one month after treatment but did not remain so at 2 months. Groups 1, 2 and 3, respectively, presented parosmia in 20/71 (28.2%), 9/22 (40.9%) and 42/71 (59.2%) patients. This difference was statistically significant between group 1 and 3 (p < 0.001). There were no patients with a worsening of the disease or an increase of the severity of the COVID-19 symptoms. Conclusions: The use of OCs in patients with OD related to mild COVID-19 is generally well-tolerated without any case of deterioration of symptoms. OC is associated with greater improvement in psychophysical olfactory evaluations at 1-month post-treatment but there was no difference at 2 months. Parosmia may be reduced following treatment with OC and NC. On the basis of these preliminary results, it is possible to state that considering the 2 months efficacy of OC and NC with respect to the OT alone and the risk-benefit ratio, the benefit to start a specific treatment of COVID-19 related OD cannot be demonstrated and there is a need for a randomised controlled trial to assess this further. [ABSTRACT FROM AUTHOR]

Background: The objective evaluation of the olfactory function of coronavirus disease 2019 patients is difficult because of logistical and operator-safety problems. For this reason, in the literature, the data obtained from psychophysical tests are few and based on small case series. Methods: A multicenter, cohort study conducted in seven European hospitals between March 22 and August 20, 2020. The Sniffin-Sticks test and the Connecticut Chemosensory Clinical Research Center orthonasal olfaction test were used to objectively evaluate the olfactory function. Results: This study included 774 patients, of these 481 (62.1%) presented olfactory dysfunction (OD): 280 were hyposmic and 201 were anosmic. There was a significant difference between self-reported anosmia/hyposmia and psychophysical test results (p = 0.006). Patients with gastroesophageal disorders reported a significantly higher probability of presenting hyposmia (OR 1.86; p = 0.015) and anosmia (OR 2.425; p < 0.001). Fever, chest pain, and phlegm significantly increased the likelihood of having hyposmia but not anosmia or an olfactory disturbance. In contrast, patients with dyspnea, dysphonia, and severe-to-critical COVID-19 were significantly more likely to have no anosmia, while these symptoms had no effect on the risk of developing hyposmia or an OD. Conclusions: Psychophysical assessment represents a significantly more accurate assessment tool for olfactory function than patient self-reported clinical outcomes. Olfactory disturbances appear to be largely independent from the epidemiological and clinical characteristics of the patients. The non-association with rhinitis symptoms and the high prevalence as a presenting symptom make olfactory disturbances an important symptom in the differential diagnosis between COVID-19 and common flu. [ABSTRACT FROM AUTHOR]

Keywords: anosmia; chest CT; coronavirus; COVID-19; hyposmia; olfactory; pneumonia; recovery; SARS-CoV-2; smell EN anosmia chest CT coronavirus COVID-19 hyposmia olfactory pneumonia recovery SARS-CoV-2 smell 103 107 5 12/31/21 20220101 NES 220101 INTRODUCTION The prognostic value of olfactory dysfunction (OD) in coronavirus disease 2019 (COVID-19) remains controversial, with conflicting reports of the association between OD and COVID-19 severity.1 Many of the prognostic studies published so far have important drawbacks that limit the reliability of the results; most are anamnestic studies that do not formally evaluate olfactory function with risk of recall bias, and use "need for hospitalization" alone to determine COVID-19 severity. Coronavirus, COVID-19, hyposmia, pneumonia, anosmia, chest CT, olfactory, recovery, SARS-CoV-2, smell At baseline, 35 patients (76.1%) had OD: 12 cases of anosmia (26.1%), severe hyposmia in 10 (21.7%), and moderate hyposmia in 13 cases (28.3%). [Extracted from the article]

Making scents of loss of taste in COVID-19: Is self-reported loss of taste due to olfactory dysfunction? Three clinical presentations were accepted for patient eligibility: isolated sudden loss of smell, isolated sudden loss of taste, or concomitant sudden loss of smell and taste. These results support the idea that most patients with COVID-19 tend to unconsciously conflate taste loss and olfactory loss, even when taste function is clearly defined to them beforehand as only referring to the perception of sweet, salty, sour, and bitter tastes. [Extracted from the article]