Taste and Smell Disorders in COVID-19 Patients: Role of Interleukin-6

IL-6 affects the severity of olfactory disorder: A cross-sectional survey of 148 patients who recovered from Omicron infection using the Sniffin' Sticks test in Tianjin, China

BACKGROUND

The mechanism of olfactory disorder (OD) in patients with COVID-19 is unclear. Our study aimed to elucidate the relationships between inflammatory factors and OD in a sample of Omicron-infected patients with a high rate of vaccination in China.

METHODS

The Sniffin' Sticks 12-item test (SST-12) was performed in a cross-sectional study of 148 recovered Omicron-infected patients to evaluate OD severity. We compared demographic, laboratory, and clinical data.

RESULTS

One hundred forty-eight Omicron-infected patients were enrolled. One hundred twenty-nine cases of OD were detected. Increased inflammation contributed to OD severity, especially in the adult group. OD was shown to be aggravated by an increase in IL-6 levels. The adjusted odds ratio was 2.22 (95% CI: 0.98-5.05, P=0.056) after adjustment for age, sex and vaccine characteristics.

CONCLUSIONS

These findings indicated that the prevalence of OD remains high in vaccinated Omicron-infected patients and that SST-12 might be a feasible method to screen for OD. IL-6 may play a role in the biochemical and pathological processes underlying OD.

Multiple Types of Taste Disorders among Patients with COVID-19

Objective Based on the increasing incidence of smell and taste dysfunction among coronavirus disease 2019 (COVID-19) patients, such issues have been considered an early symptom of infection. However, few studies have investigated the type of taste components that are most frequently affected in COVID-19 patients. This study investigated the difference in frequencies of the types of taste component disorders among hospitalized COVID-19 patients. Methods In this retrospective, single-center, observational study, patients' background characteristics, clinical course, laboratory and radiological findings, and details on taste and/or smell disorders were collected and analyzed from medical records. Patients A total of 227 COVID-19 patients were enrolled, among whom 92 (40.5%) complained of taste disorders. Results Multiple types of taste disorders (hypogeusia/ageusia and hypersensitivity, or hypersensitivity and changing tastes) were reported in 10 patients. In particular, 23 patients reported hypersensitivity to at least 1 type of taste, and 2 patients complained of a bitter taste on consuming sweet foods. Impairment of all taste components was found in 48 patients (52.2%). The most frequent taste disorder was salty taste disorder (81 patients, 89.0%). Hypersensitivity to salty taste was most frequently observed (19 patients, 20.9%). Conclusion Patients with COVID-19 develop multiple types of taste disorders, among which salty taste disorder was the most frequent, with many patients developing hypersensitivity to salty taste. As smell and taste are subjective senses, further studies with the combined use of objective examinations will be required to confirm the findings.

The Prevalence and Implications of Olfactory/Gustatory Dysfunctions among Adult COVID-19 Patients: A Retrospective Cohort Multiethnic Populations Study

(1) Background: Olfactory and gustatory dysfunctions (OGDs) was found in COVID-19 patients. Only a few studies looked into the prevalence of OGDs in the United Arab Emirates (UAE). The purpose of this study was to estimate the prevalence OGDs among multiethnic COVID-19 patients in the UAE, and its association to patients’ characteristics and disease outcomes; (2) Methods: There were 1785 COVID-19 patients included in our cohort; (3) Results: Males made up most of the study participants (86.3%). A total of 11.7% of the participants reported OGDs. Female gender and ethnicity had significantly higher symptom prevalence (p < 0.001). COVID-19 severity had a strong inverse association with OGDs (p = 0.007). Other illness outcomes, such as ICU admission, pneumonia development, and mortality, showed no correlation. Males, Asians, and patients with comorbidities all had statistically significantly lower prevalence odds. On the other hand, Emirati, Arab, and Iranian patients had a higher prevalence. COVID-19 patients with OGDs had a considerably shorter time until viral clearance than those without the symptom; (4) Conclusions: in nonsevere COVID-19, olfactory/gustatory dysfunction is common. As a result, it could be applied as a predictive sign for early disease diagnosis and prognosis.

The Prevalence and Pathophysiology of Chemical Sense Disorder Caused by the Novel Coronavirus

Emerging viral infections are a ceaseless challenge and remain a global public health concern. The world has not yet come back to normal from the devastating effects of the highly contagious and pathogenic novel coronavirus, or Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Olfactory and taste dysfunction is common in patients infected by the novel coronavirus. In light of the emergence of different coronavirus variants, it is important to update the prevalence and pathophysiology of these side effects. In this review, articles published on the prevalence of olfactory and taste dysfunction from coronavirus disease (COVID-19) and their possible pathophysiologic mechanisms have been reviewed and reported. The modulatory role of different SARS-CoV-2 variants on the chemical senses is then described. The clinical relevance of chemical sense disorder and its long-term morbidity and management is also discussed.

Gustatory dysfunction and oral ulceration in COVID-19 patients: A cross sectional study

Background

Over the past year, patients infected by severe acute respiratory syndrome coronavirus-2 presented with severe gustatory dysfunction, the prevalence of which varies among different populations. Furthermore, there have been sporadic reports of oral ulceration observed in coronavirus disease-19 (COVID-19) patients due to varied reasons. The aim of this study was to investigate and characterize the presence of gustatory disorders, oral ulceration, and other oral changes in patients with laboratory-confirmed COVID-19 infection.

Materials and Methods

In this cross-sectional observational study, a total of 402 participants who were detected COVID-19 positive by reverse transcription-polymerase chain reaction were included. Their demographic and clinical data were recorded through hospital records. The participants were interviewed either in person or on the telephone to record any change in taste and/or changes within the oral cavity. t-test for independent means was used to compare mean age, while other characteristics were compared by Chi-square test and Z-score test. P < 0.05 was taken as significant.

Results

Out of the total sample of 402 individuals, 262 were male and 140 were female. The prevalence of gustatory dysfunction and oral ulceration was 43.53% and 15.67%, respectively, in the studied sample. Significantly more females had gustatory dysfunction than males and older subjects more commonly than younger. The symptom of loss/change of taste and oral ulceration were more probable to occur together. In addition, the tongue was the most common site for ulceration in our studied sample.

Conclusion

Loss of taste is a common symptom of COVID-19 patients, whereas oral ulceration is not so commonly reported. However, the presence of both these symptoms could impair the quality of life of patients and hamper adequate nutritional uptake.

The role of cytokines and their antagonists in the treatment of COVID-19 patients

The coronavirus disease 2019 (COVID-19) has various presentations, of which immune dysregulation or the so-called cytokine storm syndrome (COVID-CSS) is prominent. Even though cytokines are vital regulators of body immunoinflammatory responses, their exaggerated release can be harmful. This hyperinflammatory response is more commonly observed during severe COVID-19 infections, caused by the excessive release of pro-inflammatory cytokines, such as interleukin-1 (IL-1), IL-6, IL-8, tumour necrosis factor, granulocyte-macrophage colony-stimulating factor, and interferon-gamma, making their blockers and antagonists of great interest as therapeutic options in this condition. Thus, the pathophysiology of excessive cytokine secretion is outlined, and their most important blockers and antagonists are discussed, mainly focussing on tocilizumab, an interleukin-6 receptor blocker approved to treat severe COVID-19 infections.

COVID-19 Induced Taste Dysfunction and Recovery: Association with Smell Dysfunction and Oral Health Behaviour

Background and Objectives: Disruption to taste and smell are common symptoms of COVID-19 infection. The current literature overlooks taste symptoms and tends to focus on the sense of smell. Persisting cases (>28 days) of taste dysfunction are increasingly recognised as a major future healthcare challenge. This study focuses on the severity and recovery of COVID-19 induced taste loss and association with olfactory symptoms, lifestyle and oral health factors. Materials and Methods: This study was a cross-sectional survey comparing 182 rapid taste recovery participants (≤28 days) with 47 participants with prolonged taste recovery >28 days. Analyses of taste loss in association with smell loss, age, sex, illness severity, diet, BMI, vitamin-D supplementation, antidepressants, alcohol use, smoking, brushing frequency, flossing, missing teeth, appliances and number of dental restorations were conducted. Differences in the severity of the loss of sour, sweet, salt, bitter and umami tastes were explored. Results: Both the severity and the duration of taste and smell loss were closely correlated (p < 0.001). Salt taste was significantly less affected than all other taste qualities (p < 0.001). Persisting taste loss was associated with older age (mean ± 95% CI = 31.73 ± 1.23 years vs. 36.66 ± 3.59 years, p < 0.001) and reduced likelihood of using floss (odds ratio ± 95% CI = 2.22 (1.15−4.25), p = 0.047). Conclusions: Smell and taste loss in COVID-19 are closely related, although a minority of individuals can experience taste or smell dysfunction in the absence of the other. The taste of salt may be less severely affected than other taste qualities and future work exploring this finding objectively is indicated. The association of flossing with rapid taste recovery adds to the growing evidence of a link between good periodontal health and favourable COVID-19 outcomes.

Changes in smell and taste perception related to COVID-19 infection: a case-control study

The main aim of the present study was to psychophysically evaluate smell and taste functions in hospitalized COVID-19 patients and to compare those results with a group of healthy subjects. Another aim of the study was to assess the relationship of changes in patients’ smell and taste functions with a number of clinical parameters, symptoms, and other physiological signs as well as with severity of disease. Olfactory and gustatory functions were tested in 61 hospitalized patients positive for SARS-CoV-2 infection and in a control group of 54 healthy individuals. Overall, we found a significant impairment of olfactory and gustatory functions in COVID-19 patients compared with the control group. Indeed, about 45% of patients self-reported complaints about or loss of either olfactory or gustatory functions. These results were confirmed by psychophysical testing, which showed a significantly reduced performance in terms of intensity perception and identification ability for both taste and smell functions in COVID-19 patients. Furthermore, gustatory and olfactory impairments tended to be more evident in male patients suffering from more severe respiratory failure (i.e., pneumonia with need of respiratory support need during hospitalization).

Is There Less Alteration of Smell Sensation in Patients With Omicron SARS-CoV-2 Variant Infection?

The ongoing pandemic Coronavirus Disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a matter of global concern in terms of public health Within the symptoms secondary to SARS-CoV-2 infection, hyposmia and anosmia have emerged as characteristic symptoms during the onset of the pandemic. Although many researchers have investigated the etiopathogenesis of this phenomenon, the main cause is not clear. The appearance of the new variant of concern Omicron has meant a breakthrough in the chronology of this pandemic, presenting greater transmissibility and less severity, according to the first reports. We have been impressed by the decrease in anosmia reported with this new variant and in patients reinfected or who had received vaccination before becoming infected. Based on the literature published to date, this review proposes different hypotheses to explain this possible lesser affectation of smell. On the one hand, modifications in the SARS-CoV-2 spike protein could produce changes in cell tropism and interaction with proteins that promote virus uptake (ACE-2, TMPRSS2, and TMEM16F). These proteins can be found in the sustentacular cells and glandular cells of the olfactory epithelium. Second, due to the characteristics of the virus or previous immunity (infection or vaccination), there could be less systemic or local inflammation that would generate less cell damage in the olfactory epithelium and/or in the central nervous system.

SARS-CoV-2 Attacks in the Brain: Focus on the Sialome

The epidemiological observations suggest that respiratory and gastrointestinal symptoms caused by severe acute respiratory coronavirus 2 (SARS-CoV-2) are accompanied by short- and long-term neurological manifestations. There is increasing evidence that the neuroinvasive potential of SARS-CoV-2 is closely related to its capacity to interact with cell membrane sialome. Given the wide expression of sialylated compounds of cell membranes in the brain, the interplay between cell membrane sialoglycans and the virus is crucial for its attachment and cell entry, transport, neuronal damage and brain immunity. Here, we focus on the significance of the brain sialome in the progress of coronavirus disease 2019 (COVID-19) and SARS-CoV-2-induced neuropathology.

Combined Nasal, Oropharyngeal Povidone Iodine Plus Glycyrrhizic Acid Sprays, Accelerate Clinical and Laboratory Recovery and Reduces Household Transmission of SARS-CoV-2: A Randomized Placebo-Controlled Clinical Trial

The COVID-19 pandemic is still posing challenging health and economic problems. Effective broad-spectrum antiviral therapy is urgently needed for the control of early SARS-CoV-2 infection to limit its spread and mutations. In this randomized placebo-controlled clinical study, we tested the effects of intranasal and oropharyngeal delivery of a compound of povidone-iodine 0.5% and glycyrrhizic acid 2.5 mg/ml on the laboratory (PCR) and clinical recovery from SARS-CoV-2 patients and their household contacts. 353 patients suspected of having COVID-19 infection were screened by chest CT and nasopharyngeal swab tests (PCR). 200 patients were randomly allocated to two equal groups: treatment and placebo groups. Treatment accelerated the recovery of PCR on days 4, 7, and 10, as evidenced by PCR-positive patients (70, vs. 99%, 20 vs. 65%, 1 vs. 10%) in both the treated and placebo groups, respectively. Treatment enhanced the early recovery of symptoms [day 7.6 ± 2 (CI 7:8.3) vs. 8.9 ± 2 (CI 8.3:9.6)]. Treatment promoted early recovery of anosmia and ageusia [5.6 ± 1 (CI, 4.8:6.4) vs. 11 ± 3 days, (CI, 10.8:12)] in both the treated and control groups (P < 0.0001). There was a notable reduction in transmission of the virus among the household close contacts in the treatment group (4%) vs. 76% in the placebo group. Combined PVI-GA nasal and oropharyngeal spray accelerates both laboratory and clinical recovery of SARS-CoV-2 infected patients in the early phases of the disease and reduces the household spread of the virus; thus, it may play an important role in controlling coronavirus outbreaks.

How common are taste and smell abnormalities in COVID-19? A systematic review and meta-analysis

OBJECTIVE

Olfactory and gustatory dysfunction (OGD) are important early clinical symptoms of COVID-19. We aim to calculate the pooled prevalence of these symptoms and discuss the likely implications on clinical practice such as their use as screening tools and potential prognosis indicators.

METHODS

Using a combination of keywords and medical subject headings, we searched for observational studies in the following five databases: Medline/PubMed, Scopus, Cochrane Library, Web of Science, and Google Scholar. Two authors independently screened and selected the final articles according to the inclusion criteria. Two investigators independently assessed the risk of bias in individual studies using the Newcastle-Ottawa Scale. Heterogeneity and publication bias were also assessed. The reported outcome of the pooled analysis was the prevalence of OGD calculated using a random-effect model. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed to report results.

RESULTS

Seventeen studies with a total sample size of 4149 were included in this meta-analysis. Out of these, 2106 and 2676 patients reported some degree of olfactory and/or gustatory dysfunction with COVID-19, respectively. The reported outcomes were in terms of pooled prevalence, with gustatory dysfunction being 57.33% and olfactory dysfunction being 59.69%, a significantly high occurrence.

CONCLUSION

There is a high occurrence of smell and taste impairment in COVID-19. Given the lack of objective testing for detecting OGD in most studies, the high prevalence found is likely to be an underestimation of the true prevalence. This implies that physicians must use them as reliable early indicators of COVID-19 and employ them before using expensive tests.

Pathogenesis of Olfactory Disorders in COVID-19

Since the outbreak of the SARS-CoV-2 pandemic, olfactory disorders have been reported as a frequent symptom of COVID-19; however, its pathogenesis is still debated. The aim of this review is to summarize the current understanding of the pathogenesis of smell impairment in the course of COVID-19 and to highlight potential avenues for future research on this issue. Several theories have been proposed to explain the pathogenesis of COVID-19-related anosmia, including nasal obstruction and rhinorrhea, oedema of the olfactory cleft mucosa, olfactory epithelial damage either within the olfactory receptor cells or the supporting non-neural cells (either direct or immune-mediated), damage to the olfactory bulb, and impairment of the central olfactory pathways. Although the pathogenesis of COVID-19-related anosmia is still not fully elucidated, it appears to be mainly due to sensorineural damage, with infection of the olfactory epithelium support cells via the ACE1 receptor and disruption of the OE caused by immense inflammatory reaction, and possibly with direct olfactory sensory neurons infection mediated by the NRP-1 receptor. Involvement of the higher olfactory pathways and a conductive component of olfactory disorders, as well as genetic factors, may also be considered.

Long-Term Subjective and Objective Assessment of Smell and Taste in COVID-19

Among the first clinical symptoms of the SARS-CoV-2 infection is olfactory−gustatory deficit; this continues for weeks and, in some cases, can be persistent. We prospectively evaluated 162 patients affected by COVID-19 using a visual analogue scale (VAS) for nasal and olfactory−gustatory symptoms. Patients were checked after 7, 14, 21, 28, 90, and 180 days. A total of 118 patients (72.8%) reported an olfactory VAS < 7 at baseline (group B), and 44 (27.2%) reported anosmia (VAS ≥ 7) (group A) and underwent the Brief Smell Identification Test (B-SIT) and Burghart Taste Strips (BTS) to quantify the deficit objectively and repeated the tests to confirm the sense recovery. Group A patients showed B-SIT anosmia and hyposmia in 44.2% and 55.8% of cases, respectively. A total of 88.6% of group A patients reported ageusia with VAS ≥ 7, and BTS confirmed 81.8% of ageusia and 18.2% of hypogeusia. VAS smell recovery was recorded starting from 14 days, with normalization at 28 days. The 28-day B-SIT score showed normosmia in 90.6% of group A patients. The mean time for full recovery (VAS = 0) was shorter in group B (22.9 days) than in group A (31.9 days). Chemosensory deficit is frequently the first symptom in patients with COVID-19, and, in most cases, recovery occurs after four weeks.

Inflawell® improves neutrophil-to-lymphocyte ratio and shortens hospitalization in patients with moderate COVID-19, in a randomized double-blind placebo-controlled clinical trial

Aims

COVID-19 is a significant global threat to public health. Despite the availability of vaccines and anti-viral drugs, there is an urgent need for alternative treatments to help prevent and/or manage COVID-19 symptoms and the underlying dysregulated immune response. We hypothesized that administration of Inflawell^® syrup, a Boswellia extract formulation enriched for boswellic acids (BAs), can reduce the excessive or persistent inflammation and thereby prevent disease progression. BAs are medicinally activated triterpenoids found in the resins of Boswellia spp., and possess an immense therapeutic potential due to their anti-inflammatory and immunoregulatory activities. We investigated the effect of Inflawell^® syrup, on moderate COVID-19 patients along with the current standard of care treatment.

Methods

A randomized placebo-controlled double-blind clinical trial was conducted, following definitive confirmation of COVID-19. Forty-seven hospitalized patients with moderate COVID-19 were enrolled and received either the Inflawell^® syrup or placebo. Clinical symptoms and markers of inflammation were evaluated at baseline and completion of the trial.

Results

Our clinical trial revealed an increase in the percentage of oxygen saturation level in patients that received the BAs compared to placebo (P < 0.0001). In addition, the average duration of hospitalization was significantly shorter in the BAs group compared with the placebo group (P < 0.04). Concomitantly, some improvement in the clinical symptoms including cough, dyspnea, myalgia, headache, and olfactory and gustatory dysfunction were detected in the BAs group. Hematologic findings showed a significant decrease in the percentage of neutrophils (P < 0.006) and neutrophil-to-lymphocyte ratio (NLR) levels (P < 0.003), associated with a significant increase in the percentage of lymphocytes in the BAs group compared with the placebo (P < 0.002). Additionally, a significant decrease in CRP, LDH, IL − 6 and TNF − α levels was detected in the BAs group. Following the intervention, fewer patients in the BAs group were PCR-positive for COVID-19 compared to placebo, though not statistically significant.

Conclusion

Overall, the treatment with Inflawell^® resulted in shorter hospital stay, alleviation of COVID-19 clinical symptoms and decline in the level of pro-inflammatory cytokines.

Trial registration

The trial has been registered in https://www.irct.ir with unique identifier: IRCT20170315033086N10 (https://en.irct.ir/trial/51631). IRCT is a primary registry in the WHO registry network (https://www.who.int/clinical-trials-registry-platform/network/primary-registries).

Relationship between Recovery from COVID-19-Induced Smell Loss and General and Oral Health Factors

Background and Objectives: Loss of smell is one of the strongest predictors of coronavirus disease 2019 (COVID-19) and can persist long after other symptoms have resolved. “Long” cases (>28 days) of smell dysfunction present future challenges to medical and dental professionals, as there is a lack of evidence on the causes and any exacerbating or relieving factors. This study aimed to explore the persistence of COVID-19-induced smell loss and association with physical, lifestyle and oral health factors. Materials and Methods: This study was a cross-sectional survey of 235 participants. Recovery of smell was explored, comparing rapid recovery (≤28 days) with prolonged recovery (>28 days). Associative factors included age, sex, illness severity, diet, BMI, vitamin D supplementation, antidepressants, alcohol use, smoking, brushing frequency, flossing, missing teeth, appliances and number of dental restorations. Results: Smell loss showed 87% resolution within 30 days. Prolonged smell loss was significantly associated with older age (mean ± 95%, CI = 31.53 ± 1.36 years for rapid recovery vs. mean ± 95%, CI = 36.0 ± 3 years for prolonged recovery, p = 0.003) and increased self-reported illness severity (mean ± 95%, CI = 4.39 ± 0.27 for rapid recovery vs. 5.01 ± 0.54 for prolonged recovery, p = 0.016). Fisher’s exact test revealed flossing was associated with rapid recovery, with flossers comprising 75% of the rapid-recovery group, compared to 56% in the prolonged-recovery group (odds ratio ± 95%, CI = 2.26 (1.23–4.15), p = 0.01). All other factors were not significantly associated (p > 0.05). Conclusions: Increased age and illness severity were associated with prolonged smell recovery. Use of floss was the only modifiable factor associated with rapid recovery of smell loss. As 87% of cases resolve within 30 days, future studies may benefit from targeted recruitment of individuals experiencing prolonged sense loss. This would increase statistical confidence when declaring no association with the other factors assessed, avoiding type II errors.

COVID-19 Infection in Children and Infants: Current Status on Therapies and Vaccines

Since the beginning in December 2019, the SARS-CoV-2 outbreak appeared to affect mostly the adult population, sparing the vast majority of children who only showed mild symptoms. The purpose of this investigation is to assess the status on the mechanisms that give children and infants this variation in epidemiology compared to the adult population and its impact on therapies and vaccines that are aimed towards them. A literature review, including in vitro studies, reviews, published guidelines and clinical trials was performed. Clinical trials concerned topics that allowed a descriptive synthesis to be produced. Four underlying mechanisms were found that may play a key role in providing COVID-19 protection in babies. No guidelines are available yet for therapy due to insufficient data; support therapy remains the most used. Only two vaccines are approved by the World Health Organization to be used in children from 12 years of age, and there are currently no efficacy or safety data for children below the age of 12 years. The COVID-19 clinical frame infection is milder in children and adolescents. This section of the population can act as vectors and reservoirs and play a key role in the transmission of the infection; therefore, vaccines are paramount. More evidence is required to guide safely the vaccination campaign.

Self-reported symptom study of COVID-19 chemosensory dysfunction in Malaysia

Alterations in the three chemosensory modalities-smell, taste, and chemesthesis-have been implicated in Coronavirus Disease 2019 (COVID-19), yet emerging data suggest a wide geographic and ethnic variation in the prevalence of these symptoms. Studies on chemosensory disorders in COVID-19 have predominantly focused on Caucasian populations whereas Asians remain understudied. We conducted a nationwide, multicentre cross-sectional study using an online questionnaire on a cohort of RT-PCR-confirmed adult COVID-19 patients in Malaysia between 6 June and 30 November 2020. The aim of our study was to investigate their presenting symptoms and assess their chemosensory function using self-ratings of perceived smell, taste, chemesthesis, and nasal blockage. In this cohort of 498 patients, 41.4% reported smell and/or taste loss when diagnosed with COVID-19, which was the commonest symptom. Blocked nose, loss of appetite, and gastrointestinal disturbances were independent predictors of smell and/or taste loss on multivariate analysis. Self-ratings of chemosensory function revealed a reduction in smell, taste, and chemesthesis across the entire cohort of patients that was more profound among those reporting smell and/or taste loss as their presenting symptom. Perceived nasal obstruction accounted for only a small proportion of changes in smell and taste, but not for chemesthesis, supporting viral disruption of sensorineural mechanisms as the dominant aetiology of chemosensory dysfunction. Our study suggests that chemosensory dysfunction in COVID-19 is more widespread than previously reported among Asians and may be related to the infectivity of viral strains.Study Registration: NMRR-20-934-54803 and NCT04390165.

The impact of COVID-19-related smell and taste disorders on a patient with bulimia nervosa: a case report

A large number of patients with COVID-19 will suffer from long-term smell and taste disorders (STD). These STD symptoms could have a significant impact on patients with an eating disorder (ED). To highlight this issue, a case is presented of a patient with bulimia nervosa who experienced COVID-19-relate STD symptoms. Clinicians should reassess patients with an ED who suffer from COVID-19 with STD symptomatology and potentially redirect treatment. More research is needed on STD symptoms in patients with an ED to improve our knowledge on the role of smell and taste in disordered eating behaviors and improve treatment guidelines.

The Oral Complications of COVID-19

Background: COVID-19 is a novel coronavirus infectious disease associated with the severe acute respiratory syndrome. More and more patients are being cured due to the development of clinical guidelines for COVID-19 pneumonia diagnosis, treatment, and vaccines. However, the long-term impact of COVID-19 on patients after recovery is unclear. Currently available reports have shown that patients recovered from COVID-19 continue to experience health problems in respiratory and other organ systems. Oral problem is one of the important complications which has serious impacts on the rehabilitation and future quality of life, such as ageusia and macroglossia, but the oral complication is often being neglected.

Aim of Review: From the perspective of stomatology, we summarized and elaborated in detail the types, pathogenesis of oral complications from COVID-19 patients after rehabilitation, and the reported prevention or treatment recommendations which may improve the COVID-19 patients associated oral diseases.

Key Scientific Concepts of Review: 1) To understand the common oral complications and the mechanisms of the development of oral complications after the COVID-19 recovery; 2) To summary the practical strategies to prevent the oral complications and construct the rehabilitation plans for patients with oral complications.

Olfactory Dysfunction in Patients With Coronavirus Disease 2019: A Review

The coronavirus disease 2019 (COVID-19) pandemic is wreaking havoc on public-health and economic systems worldwide. Among the several neurological symptoms of patients with COVID-19 reported in clinical practice, olfactory dysfunction (OD) is the most common. OD occurs as the earliest or the only clinical manifestation in some patients. Increasing research attention has focused on OD, which is listed as one of the main diagnostic symptoms of severe acute respiratory syndrome-coronavirus-2 infection. Multiple clinical and basic-science studies on COVID-19-induced OD are underway to clarify the underlying mechanism of action. In this review, we summarize the clinical characteristics, mechanisms, evaluation methods, prognosis, and treatment options of COVID-19-induced OD. In this way, we hope to improve the understanding of COVID-19-induced OD to aid early identification and precise intervention.

No lasting impact of Covid-19 on the auditory system: a prospective cohort study

Objective

Otological complications are considered early symptoms of severe acute respiratory syndrome coronavirus-2; however, it is unknown how long these symptoms last and whether the virus leaves any hearing disorders post-recovery.

Methods

This prospective cohort study comprised 31 mild or moderate confirmed coronavirus disease 2019 patients and 26 age-matched control peers (21–50 years old). Patients were questioned about their otological symptoms, and their hearing status was assessed during one month post-diagnosis.

Results

Patients showed a significantly higher rate of otological symptoms (hearing loss, ear fullness, ear pain, dizziness or vertigo, communication difficulties, and hyperacusis) versus the control group (p ≤ 0.022). The symptoms resolved early, between 2 and 8 days after their appearance. No significant differences were observed between the two groups in pure tone and extended high-frequency audiometry, transient evoked otoacoustic emissions, distortion product otoacoustic emissions, or auditory brainstem response following recovery.

Conclusion

The findings indicate that, in mild to moderate coronavirus disease 2019 cases, otological symptoms resolve within a week, and the virus has no lasting impact on the auditory system.

Dysgeusia: A review in the context of COVID-19

Background

Taste disorders in general, and dysgeusia in particular, are relatively common disorders that may be a sign of a more complex acute or chronic medical condition. During the COVID-19 pandemic, taste disorders have found their way into the realm of general as well as specialty dentistry, with significance in screening for patients who potentially may have the virus.

Types of Studies Reviewed

The authors searched electronic databases (PubMed, Embase, Web of Science, Google Scholar) for studies focused on dysgeusia, ageusia, and other taste disorders and their relationship to local and systemic causes.

Results

The authors found pertinent literature explaining the normal physiology of taste sensation, proposals for suggested new tastes, presence of gustatory receptors in remote tissues of the body, and etiology and pathophysiology of taste disorders, in addition to the valuable knowledge gained about gustatory disorders in the context of COVID-19. Along with olfactory disorders, taste disorders are one of the earliest suggestive symptoms of COVID-19 infection.

Conclusions

Gustatory disorders are the result of local or systemic etiology or both. Newer taste sensations, such as calcium and fat tastes, have been discovered, as well as taste receptors that are remote from the oropharyngeal area. Literature published during the COVID-19 pandemic to date reinforces the significance of early detection of potential patients with COVID-19 by means of screening for recent-onset taste disorders.

Practical Implications

Timely screening and identification of potential gustatory disorders are paramount for the dental care practitioner to aid in the early diagnosis of COVID-19 and other serious systemic disorders.

Direct and Indirect Neurological Signs of COVID-19

Objective. To systematize the neurological manifestations of COVID-19. Materials and methods. A systematic computerized analysis of all currently available publications on the neurological manifestations of COVID-19 was undertaken (2374 reports in PubMed) by topological data analysis. Results. A set of interactions between infection with SARS-CoV-2, metabolic impairments affecting neurotransmitters (acetylcholine, dopamine, serotonin, and GABA), enkephalins, and neurotrophins, micronutrients, chronic and acute inflammation, encephalopathy, cerebral ischemia, and neurodegeneration (including demyelination) was described. The most typical neurological manifestations of COVID-19 were anosmia/ageusia due to ischemia, neurodegeneration, and/or systematic increases in proinflammatory cytokine levels. COVID-19 provoked ischemic stroke, Guillain–Barré syndrome, polyneuropathy, encephalitis, meningitis, and parkinsonism. Coronavirus infection increased the severity of multiple sclerosis and myopathies. The possible roles of the human virome in the pathophysiology of COVID-19 are considered. A clinical case of a patient with neurological complications of COVID-19 is described. Conclusions. In the long-term perspective, COVID-19 promotes increases in neurodegenerative changes, which requires special neurological rehabilitation programs. Use of cholinergic drugs and antihypoxic agents compatible with COVID-19 therapy is advised.

Molecular mimicry of NMDA receptors may contribute to neuropsychiatric symptoms in severe COVID-19 cases

Approximately 30% of individuals with severe SARS-CoV-2 infections also develop neurological and psychiatric complaints. In rare cases, the occurrence of autoimmune encephalitis has been reported after SARS-CoV-2 infection. In this systematic review, we have identified eight SARS-CoV-2-associated cases of anti-NMDA receptor encephalitis. All had cerebrospinal fluid antibodies against the NMDA receptor and a recent onset of working memory deficits, altered mental status, or psychiatric symptoms, such as confusion, agitation, auditory hallucination, catatonia and speech dysfunction. All patients received high-dose steroid and immunoglobulin therapeutics and conditions improved in each case. These findings suggest that clinical attention should be paid to warning signs of autoimmune encephalitis in severe COVID-19 cases. If characteristic features of autoimmune encephalitis are present, autoantibody diagnostics should be performed and confirmed cases should be treated with immunotherapy to minimize neurological impairments.

Mechanism of Anosmia Caused by Symptoms of COVID-19 and Emerging Treatments

The occurrence of anosmia, the loss or change in sense of smell, is one of the most common symptoms of COVID-19 experienced by almost 53% of those affected. Several hypotheses explain the mechanism of anosmia in patients suffering from COVID-19. This study aims to review the related mechanisms and answer the questions regarding COVID-19-related anosmia as well as propose a new strategy for treatment of long-term anosmia as a result of COVID-19 infection. This paper covers all of the studies investigating olfactory disorders following COVID-19 infection and explains the possible reasons for the correlated anosmia, including olfactory cleft syndrome, local inflammation in the nasal epithelium, early apoptosis of olfactory cells, changes in olfactory cilia and odor transmission, damage to microglial cells, effect on olfactory bulbs, epithelial olfactory injury, and impairment of olfactory neurons and stem cells. The key questions that arise in this field have been discussed, such as why prevalent anosmia is varied among the age categories and among sexes and the correlation of anosmia with mild or severe COVID-19 infection. The angiotensin-converting enzyme 2 receptor is a significant player in the mechanism of anosmia in COVID-19 patients. Based on current studies, a novel approach to treat long-COVID-19 with ongoing anosmia has been proposed. The fields of smart drug delivery, tissue engineering, and cell therapy provide a hypothesized strategy that can minimize the side effects of current treatments and support efficient recovery of the olfactory system.

Olfactory dysfunction in aging and neurodegenerative diseases

Alterations in olfactory functions are proposed to be early biomarkers for neurodegeneration. Many neurodegenerative diseases are age-related, including two of the most common, Parkinson's disease (PD) and Alzheimer's disease (AD). The establishment of biomarkers that promote early risk identification is critical for the implementation of early treatment to postpone or avert pathological development. Olfactory dysfunction (OD) is seen in 90% of early-stage PD patients and 85% of patients with early-stage AD, which makes it an attractive biomarker for early diagnosis of these diseases. Here, we systematically review widely applied smelling tests available for humans as well as olfaction assessments performed in some animal models and the relationships between OD and normal aging, PD, AD, and other conditions. The utility of OD as a biomarker for neurodegenerative disease diagnosis and future research directions are also discussed.

COVID-19 pandemic and reasons to prioritize the needs of the health care system to ensure its sustainability: A scoping review from January to October 2020 (Review)

The worldwide spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) led the World Health Organization to characterize the pandemic as a public health emergency of international concern. National health care systems in countries during the initial surge of the pandemic were unable to handle the sanitarian crisis that had emerged. Thus, the prevention and control of future global health emergencies must be a priority. The present scoping review aimed to retrieve articles that summarize the current experience on issues related to historical knowledge, and epidemiology, clinical features and overall burden of SARS-CoV-2 on health care services. In summary, a comprehensive overview of the information that has been learnt during this period is presented in the current review. Furthermore, taking into account the global experience, the need for planning cohesive and functional health services before similar pandemic events occur in the future is highlighted. The next public health issue should be prevented rather than treated. In spite of the vaccination benefits, a number of sporadic cases of SARS-CoV-2infections will persist. Information collected remains relevant for appraising how similar threats can be faced in the future. Overall, collaborative health care plans need to be rethought to increase preparedness.

Assessing the extent and timing of chemosensory impairments during COVID-19 pandemic

Chemosensory impairments have been established as a specific indicator of COVID-19. They affect most patients and may persist long past the resolution of respiratory symptoms, representing an unprecedented medical challenge. Since the SARS-CoV-2 pandemic started, we now know much more about smell, taste, and chemesthesis loss associated with COVID-19. However, the temporal dynamics and characteristics of recovery are still unknown. Here, capitalizing on data from the Global Consortium for Chemosensory Research (GCCR) crowdsourced survey, we assessed chemosensory abilities after the resolution of respiratory symptoms in participants diagnosed with COVID-19 during the first wave of the pandemic in Italy. This analysis led to the identification of two patterns of chemosensory recovery, partial and substantial, which were found to be associated with differential age, degrees of chemosensory loss, and regional patterns. Uncovering the self-reported phenomenology of recovery from smell, taste, and chemesthetic disorders is the first, yet essential step, to provide healthcare professionals with the tools to take purposeful and targeted action to address chemosensory disorders and their severe discomfort.

What can the neurological manifestations of COVID-19 tell us: a meta-analysis

Background

Covid-19 became a global pandemic in 2019. Studies have shown that coronavirus can cause neurological symptoms, but clinical studies on its neurological symptoms are limited. In this meta-analysis, we aimed to summarize the various neurological manifestations that occurred in COVID-19 patients and calculate the incidence of various neurological manifestations. At the same time, we further explored the mechanism of nervous system injury and prognosis in COVID-19 patients in combination with their nervous system manifestations. This study provides a reference for early clinical identification of COVID-19 nervous system injury in the future, so as to achieve early treatment and reduce neurological sequelae.

Methods

We systematically searched all published English literature related to the neurological manifestations of COVID-19 from January 1, 2020, to April 30, 2021, in Pubmed, Embase, and Cochrane Library. The keywords used were COVID-19 and terminology related to the nervous system performance. All included studies were selected by two independent reviewers using EndNote and NoteExpress software, any disagreement was resolved by consensus or by a third reviewer, and the selected data were then collected for meta-analysis using a random-effects model.

Results

A total of 168 articles (n = 292,693) were included in the study, and the meta-analysis showed that the most common neurological manifestations of COVID-19 were myalgia(33%; 95%CI 0.30–0.37; I² = 99.17%), smell impairment(33%; 95%CI 0.28–0.38; I² = 99.40%), taste dysfunction(33%; 95%CI 0.27–0.39; I² = 99.09%), altered mental status(32%; 95%CI 0.22–0.43; I² = 99.06%), headache(29%; 95%CI 0.25–0.33; I² = 99.42%), encephalopathy(26%; 95%CI 0.16–0.38; I² = 99.31%), alteration of consciousness(13%; 95%CI 0.08–0.19; I² = 98.10%), stroke(12%; 95%CI 0.08–0.16; I² = 98.95%), dizziness(10%; 95%CI 0.08–0.13; I² = 96.45%), vision impairment(6%; 95%CI 0.03–0.09; I² = 86.82%), intracerebral haemorrhage(5%; 95%CI 0.03–0.09; I² = 95.60%), seizure(4%; 95%CI 0.02 -0.05; I² = 98.15%), encephalitis(2%; 95%CI 0.01–0.03; I² = 90.36%), Guillan-Barré Syndrome (GBS) (1%; 95%CI 0.00–0.03; I² = 89.48%).

Conclusions

Neurological symptoms are common and varied in Covid-19 infections, and a growing number of reports suggest that the prevalence of neurological symptoms may be increasing. In the future, the role of COVID-19 neurological symptoms in the progression of COVID-19 should be further studied, and its pathogenesis and assessment methods should be explored, to detect and treat early neurological complications of COVID-19 and reduce mortality.

Gustatory dysfunction in COVID-19 patients: a rapid systematic review on 27,687 cases

Objective: This is a rapid systematic review concerning taste alterations in 27,687 individuals infected with SARS-CoV-2, published in the worldwide literature.Material and methods: Of the 485 articles recovered, 67 eligible studies (27,687 confirmed COVID-19 cases) were included in this analysis. We analysed the prevalence of the taste alterations in patients considering the country of origin of the studies.Results: The results show strong important differences in the overall reported prevalence of taste alterations among the different countries (from 11% of Korea to 88.8% of Belgium).Conclusions: These data highlight that there is a different geographical distribution of taste alterations in COVID-19 patients. Gustatory dysfunction seems to be an understudied symptom of COVID-19 and this may explain the inconsistencies of diagnostic criteria for COVID-19 case definition. Furthermore, this diagnostic underestimation can lead to an increased risk of contagion for the whole population and for the working classes most at risk, including the dental one.

Sars-CoV-2 Virus Infection May Interfere CD34+ Hematopoietic Stem Cells and Megakaryocyte-Erythroid Progenitors Differentiation Contributing to Platelet Defection towards Insurgence of Thrombocytopenia and Thrombophilia

To date, several cases of thrombosis have been confirmed to be related to Sars-CoV-2 infection. Multiple attempts detected the prolonged occurrence of Sars-CoV-2 viral RNA (long COVID) in whole blood suggesting that virus byproducts may remain within cells and tissues well over the disease has finished. Patients may develop severe thrombocytopenia, acute anemia of inflammation and, systemic thrombosis with the fatal course of disease, which is suggestive of further interferences of Sars-CoV-2 on hematopoietic stem cells (HSCs) within the differentiation process towards erythroid and megakaryocytic cells. Therefore, we speculated whether Sars-CoV-2 propagates in or compartmentalizes with hematopoietic progenitor, erythroid, and megakaryocytic cells as the main cause of thrombotic events in either COVID-19 patients or vaccinated individuals. Results: The Sars-CoV-2 RNA replication, protein translation and infectious particle formation as the spike proteins in hematopoietic cell lines take place via the angiotensin-converting enzyme 2 (ACE2) entry pathway within primary CD34⁺ HSCs inducing, ex vivo, the formation of defected erythroid and megakaryocytic cells that eventually become targets of humoral and adaptive immune cells. Conclusions: Viral particles from affected CD34⁺ HSCs or the cellular component of RBC units and eventually platelets, present the greatest risk for sever thrombosis-transmitted Sars-CoV-2 infections.

Age-dependent appearance of SARS-CoV-2 entry sites in mouse chemosensory systems reflects COVID-19 anosmia-ageusia symptoms

COVID-19 pandemic has given rise to a collective scientific effort to study its viral causing agent SARS-CoV-2. Research is focusing in particular on its infection mechanisms and on the associated-disease symptoms. Interestingly, this environmental pathogen directly affects the human chemosensory systems leading to anosmia and ageusia. Evidence for the presence of the cellular entry sites of the virus, the ACE2/TMPRSS2 proteins, has been reported in non-chemosensory cells in the rodent’s nose and mouth, missing a direct correlation between the symptoms reported in patients and the observed direct viral infection in human sensory cells. Here, mapping the gene and protein expression of ACE2/TMPRSS2 in the mouse olfactory and gustatory cells, we precisely identify the virus target cells to be of basal and sensory origin and reveal the age-dependent appearance of viral entry-sites. Our results propose an alternative interpretation of the human viral-induced sensory symptoms and give investigative perspectives on animal models.

Brechbühl et al characterise the gene and protein expression of ACE2/TMPRSS2 in the mouse olfactory and gustatory cells, which reveals that SARS-CoV-2 target cells are of basal and sensory origin. They also demonstrate an age-dependent appearance of viral entry-sites, which could inform the use of mouse models in the investigation of SARS-CoV-2 effects on olfaction.

The unfolding palette of COVID-19 multisystemic syndrome and its neurological manifestations

Although our current knowledge of the pathophysiology of COVID-19 is still fragmentary, the information so far accrued on the tropism and life cycle of its etiological agent SARS-CoV-2, together with the emerging clinical data, suffice to indicate that the severe acute pulmonary syndrome is the main, but not the only manifestation of COVID-19. Necropsy studies are increasingly revealing underlying endothelial vasculopathies in the form of micro-haemorrhages and micro-thrombi. Intertwined with defective antiviral responses, dysregulated coagulation mechanisms, abnormal hyper-inflammatory reactions and responses, COVID-19 is disclosing a wide pathophysiological palette. An additional property in categorising the disease is the combination of tissue (e.g. neuro- and vasculo-tropism) with organ tropism, whereby the virus preferentially attacks certain organs with highly developed capillary beds, such as the lungs, gastrointestinal tract, kidney and brain. These multiple clinical presentations confirm that the acute respiratory syndrome as described initially is increasingly unfolding as a more complex nosological entity, a multiorgan syndrome of systemic breadth. The neurological manifestations of COVID-19, the focus of this review, reflect this manifold nature of the disease.

The effect of coronaviruses on olfaction: systematic review

BACKGROUND

Unlike other respiratory viruses, SARS-CoV-2 causes anosmia without sinonasal inflammation. Here we systematically review the effects of the 7 known human coronaviruses on olfaction to determine if SARS-CoV-2 distinctly affects the olfactory system.

METHOD

PubMed, EMBASE, Web of Science, bioRxiv, medRxiv and DOAJ were searched for studies describing pathophysiological, immunohistochemical, cytological and clinical data.

RESULTS

49 studies were included. Common cold coronaviruses lead to sinonasal inflammation which can cause transient and chronic loss of smell. MERS-CoV entry receptors were not found in the nasal mucosa and it did not impair olfaction. SARS-CoV-1 had low affinity for its receptor ACE2, limiting olfactory effects. Anosmia is frequent in SARS-CoV-2 infections. SARS-CoV-2’s entry factors ACE2 and TMPRSS2 are expressed in the nasal respiratory epithelium and olfactory supporting cells. SARS-CoV-2 appeared to target the olfactory cleft while diffuse nasal inflammation was not observed. Damage of the olfactory epithelium was observed in animal models. Alternative receptors such as furin and neuropilin-1 and the similarity of viral proteins to odourant receptors could amplify olfactory impairment in SARS-CoV-2 infection.

CONCLUSIONS

The pathophysiology of anosmia in SARS-CoV-2 infection is distinct from other coronaviruses due to preferentially targeting olfactory supporting cells. However, SARS-CoV-2 does not cause sinonasal inflammation in spite of preferred entry factor expression in the nasal respiratory epithelium. This raises doubts about the attention given to ACE2. Alternative receptors, odourant receptor mimicry and other as yet unknown mechanisms may be crucial in the pathogenesis of anosmia in SARS-CoV-2 infection. Further studies are warranted to investigate infection mechanisms beyond ACE2.

Does serotonin deficiency lead to anosmia, ageusia, dysfunctional chemesthesis and increased severity of illness in COVID-19?

Different mechanisms forwarded to understand anosmia and ageusia in coronavirus patients are not adequate to explain reversible anosmia and ageusia, which are resolved quickly. In addition, the reason behind the impaired chemesthetic sensations in some coronavirus patients remains unknown. In the present paper it is proposed that SARS-CoV-2 patients suffer from depletion of tryptophan, as ACE2, a key element in the process of absorption of tryptophan from the food, is significantly reduced in the patients as coronavirus uses ACE2 as the receptor to enter the host cells. The tryptophan depletion leads to a deficit of serotonin (5-HT) in SARS-COV-2 patients because tryptophan is the precursor in the synthesis of 5-HT. Such 5-HT deficiency can explain anosmia, ageusia and dysfunctional chemesthesis in COVID-19, given the fact that 5-HT is an important neuromodulator in the olfactory neurons, taste receptor cells and transient receptor potential channels (TRP channels) involved in chemesthesis. In addition, 5-HT deficiency worsens silent hypoxemia and depresses hypoxic pulmonary vasoconstriction leading to increased severity of the disease. Also, the levels of anti-inflammatory melatonin (synthesized from 5-HT) and nicotinamide adenine dinucleotide (NAD⁺, produced from niacin whose precursor is the tryptophan) might decrease in coronavirus patients resulting in the aggravation of the disease. Interestingly, selective serotonin reuptake inhibitors (SSRIs) may not be of much help in correcting the 5-HT deficiency in COVID-19 patients, as their efficacy goes down significantly when there is depletion of tryptophan in the system. Hence, tryptophan supplementation may herald a radical change in the treatment of COVID-19 and accordingly, clinical trials (therapeutic / prophylactic) should be conducted on coronavirus patients to find out how tryptophan supplementation (oral or parenteral, the latter in severe cases where there is hardly any absorption of tryptophan from the food) helps in curing, relieving or preventing the olfactory, gustatory and chemesthetic dysfunctions and in lessening the severity of the disease.

Pathophysiology and possible treatments for olfactory-gustatory disorders in patients affected by COVID-19

SARS-CoV-2 infects host cells mainly through the interaction between the virus's Spike protein and the viral receptors namely Angiotensin-Converting Enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2). Both are highly expressed in the gastrointestinal tract, in the nasal and bronchial epithelium, as well as in the type II alveolar epithelial cells. The aim of this review is to report the evidences from the scientific literature on the pathophysiology and the available treatments for olfactory-gustatory disorders in patients with COVID-19. The mechanisms involved in these disorders are still unclear and studies on specific therapies are scarce. However, it has been hypothesized that a decrease in the sensitivity of the sensory neurons as well as the co-expression of ACE2 and TMPRSS2 in the alveolar epithelial cells are the main causes of olfactory-gustatory disorders. The possible mechanisms described in the literature for changes in taste perception in patients with COVID-19 include olfactory disorders and a competitive activity of COVID-19 on ACE2 receptors in the taste buds. In addition, SARS-CoV-2 can bind to sialic acid receptors in the taste buds. In general, evidences show that there is no specific treatment for olfactory-taste disorders induced by SARS-CoV-2, even though some treatments have been used and have shown some promising results, such as olfactory training, intranasal application of sodium citrate and vitamin A, as well as systemic use of omega-3 and zinc. Corticosteroids have also been used as a pharmacological approach to treat patients with olfactory dysfunction with some contradictory results. The knowledge of the mechanisms by which SARS-CoV-2 influences the sensory systems and how effective therapies can treat the loss of smell and taste will have important implications on the understanding and clinical management of olfactory-taste disorders.

Evaluation of Vitamin D (25OHD), Bone Alkaline Phosphatase (BALP), Serum Calcium, Serum Phosphorus, Ionized Calcium in Patients with Mandibular Third Molar Impaction. An Observational Study

The aim of this study was to evaluate the levels of vitamin D (25OHD) and other bone biomarkers in patients with third molar impaction (TMI). Thirty males and 30 females with unilateral or bilateral impacted mandibular third molar, and 15 males and 15 females as a control group (CG) were recruited. Rx-OPT was used to evaluate dental position and Pederson index to measure the difficulty of the intervention. Bone biomarkers were measured through blood venous sample in TMI group and CG. Mann-Whitney test, Pearson’s correlation coefficient, linear regression model were used to compare the different parameters in the two groups. 25OHD showed lower values in TMI group than in CG (p < 0.05) with values significantly lower in bilateral impaction (p < 0.05). Pearson’s coefficient for 25OHD presented a negative correlation with the Pederson index (ρ = −0.75). Bone alkaline phosphatase (BALP) showed significantly lower dosage in TMI group than CG (p = 0.02), Pearson’s coefficient for BALP presented a negative correlation with the Pederson index. Serum calcium, serum phosphorus, ionized calcium levels in TMI and CG groups were similar and Mann-Whitney test did not significantly differ between TMI and CG. TMI could be a sign of vitamin D deficiency and of low BALP levels that should be investigated.

Olfactory and taste dysfunctions in COVID-19

PURPOSE OF REVIEW

Olfactory dysfunction (OD) can be a single and early prominent symptom of severe acute respiratory syndrome (SARS)-COV-2 infection unlike middle east respiratory syndrome (MERS) and SARS. OD data are very informative but many are not peer-reviewed, often inconclusive and may reveal variable and sometimes contradictory results. This is often due to incongruent data of subjective and objective OD testing. Mechanistic pathways of OD and taste dysfunction (TD) are slowly unveiling, not infrequently extrapolated from historical models of SARS and MERS and are still partly unclear.

RECENT FINDINGS

We reviewed the literature on OD and TD during the COVID-19 pandemic analyzing current data on pathogenesis and clinical correlates including prevalence, recovery rates, risk factors, and predictive power. Also, we evaluated various methods of subjective and objective olfactory testing and discussed challenges in management of patients with OD and rhinitis during the pandemic.

SUMMARY

Subjective evaluation of smell disturbances during COVID-19 pandemic likely underestimates true prevalence, severity, and recovery rates of OD when compared to objective testing. OD is predictive of COVID-19 infection, more so when associated with TD. Recognizing inherent limitations of both subjective and objective OD and TD testing enables us better to manage chemosensory dysfunction in COVID-19 patients. Besides, current mechanistic data suggest neurotropism of COVID-19 for olfactory neuro-epithelium and a potential role of transient receptor potential (TRP) channels. Future studies are needed to explore further the neurogenic inflammation in COVID-19.

To Detect and Reject, Parallel Roles for Taste and Immunity

PURPOSE OF REVIEW

From single cells to entire organisms, biological entities are in constant communication with their surroundings, deciding what to 'allow' in, and what to reject. In very different ways, the immune and taste systems both fulfill this function, with growing evidence suggesting a relationship between the two, through shared signaling pathways, receptors, and feedback loops. The purpose of this review was to explore recent reports on taste and immunity in model animals and in humans to explore our understanding of the interplay between these systems.

RECENT FINDINGS

Acute infections in the upper airway, as with SARS-CoV-2, are associated with a proinflammatory state, and blunted taste perception. Further, recent findings highlight taste receptors working as immune sentinels throughout the body. Work in humans and mice also points to inflammation from obesity impacting taste, altering taste bud abundance and composition. There is accumulating evidence that taste cells, and particularly their receptors, play a role in airway and gut immunity, responsive to invading organisms. Inflammation itself may further act on taste buds and other taste receptor expressing cells throughout the body as a form of homeostatic control.

Cardiac Involvement in COVID-19 Patients: A Contemporary Review

Background: The widely variable clinical manifestations of SARS-CoV2 disease (COVID-19) range from asymptomatic infections to multiple organ failure and death. Among the organs affected is the heart. This does not only affect people who already have previous cardiovascular problems, but also healthy people. This is a reason not to overlook any symptoms or to perform targeted examinations, even if apparently unrelated to the heart, for quick recognition and timely therapy. Aim of the study: This review recapitulates the current state of knowledge on the potential mechanisms and manifestation of myocarditis in patients with COVID-19 infection. Methods: A web-based search of published data was performed for all relevant studies on patients diagnosed with a COVID-19-induced acute myocarditis, and a total of 50 reports were included. The analysis of the studies evaluated highlights a male predominance, with the average age of patients being 55 years. The most common presenting symptoms included fever, shortness of breath, cough, and chest pain. Among ECG changes, non-specific ST-segment and T-wave amplitude alterations and ventricular tachycardia episodes were reported. Finally, we wanted to use a general evaluation without distinguishing between various countries, taking into consideration only the peer or reviewer, regardless of the declared value of the journals that have been published. Results and critical findings: The most common presenting symptoms included fever, shortness of breath, cough, and chest pain. Among ECG changes, non-specific ST-segment and T-wave amplitude alterations and ventricular tachycardia episodes were reported. In most patients, elevated levels of cardiac and inflammatory biomarkers were measured. Left ventricular dysfunction and hypokinesis were commonly exhibited symptoms. Cardiac Magnetic Resonance Imaging (CMRI) confirmed the diagnosis of myocarditis with features of cardiac edema and cardiac injury. Nine patients underwent histopathological examination. Treatment with corticosteroids and immunoglobulins was the most applied strategy following the administration of antivirals. Discussion: Despite the exponentially growing knowledge on the management of COVID-19 infection, current available data on SARS-CoV2-correlated myocarditis are still limited, and several difficulties may be encountered in the differential diagnosis of acute myocarditis in the context of COVID-19 disease. Conclusions: While diagnostic criteria and evaluation strategies for myocarditis are well described, no guidelines for the diagnosis and treatment of myocarditis in COVID-19 patients have yet been established. Therefore, further research is needed to advance the understanding of this disease process and define the most appropriate strategic approach in these patients.

TLR4 as a therapeutic target for respiratory and neurological complications of SARS-CoV-2

Introduction: The COVID-19 pandemic remains aglobal challenge. While there are mRNA agents on the horizon as apotential prevention, adefinitive drug therapy is an unmet medical need. The hyperinflammatory response, known as the 'cytokine storm', is chiefly responsible for complications and deaths. The binding of spike-glycoprotein of SARS-CoV-2 to TLR4 receptors has been documented in several studies and has been found to play arole in hyperinflammation; hence, there is an interest in TLR4 as apotential drug target.Areas covered: This review discusses the neurological and respiratory complications of SARS-CoV-2 infection and progresses to examine the role of the 'cytokine storm' and the involvement of TLR4 receptors in these complications. The possibility of using TLR4 modulators to curb the complications are considered and finally, ashort perspective on future potential drug treatments is offered. Various databases were searched including Pub-Med, Google Scholar, and Medline. The search mainly included research articles, meta-analysis, retrospective studies, reports, and systematic reviews.Expert opinion: TLR4 modulators are being investigated in clinical trials for COVID-19. Challenges in terms of structural diversity of the agents, their natural origin, and efficacy demand extensive research.

Smell and Taste Disturbance in COVID-19 Patients: A Prospective Multicenteric Review

To study the incidence of the smell and taste disturbance in the COVID-19 patients and a follow up at 4 months to observe for the duration of resolution of these symptoms. This is a multicentric prospective study carried out in 3 different countries, from April, 2020 to January, 2021. The COVID-19 positive patients, aged between 15 and 60 years, were inquired about the presence of any smell or taste related symptoms. The same patients were followed up with the telephonic interview after 2 months and then after 4 months, respectively. The duration of resolution of the smell and taste disturbance symptoms was noted. Total of 188 COVID-19 positive patients, average age 33.1 ± 1.7 years, 54.2% males and 45.8% female were included in the study. The smell disturbance was present in 60.6% (hyposmia 36.1%, anosmia 20.2%, and parosmia 4.2%) and taste disturbance in 28.7% of patients (hypogeusia 20.2%, ageusia 6.9%, and parageusia 1.6%). There was improvement of anosmia by 97.4, hyposmia by 95.6%, parosmia by 100%, ageusia by 100%, hypogeusia 94.8%, and parageusia by 66.7%, at 4 months follow up. The present study concludes that the smell and taste disturbances are one of the main early presenting features of the COVID-19 infection. The temporary effect of the COVID-19 infection on the olfactory and gustatory pathway was also highlighted with more than 95% patients improving at 4 months of follow up.

Correlations between IL-6 serum level and olfactory dysfunction severity in COVID-19 patients: a preliminary study

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 (r_s = 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.