Can photobiomodulation restore anosmia and ageusia induced by COVID-19? A pilot clinical study.

Along with other COVID-19 clinical manifestations, management of both olfactory and gustatory dysfunction have drawn a considerable attention. Photobiomodulation (PBM) has emerged to be a possible effective therapy in restoring taste and smell functionality, but the evidence is scarce. Hence, the present pilot study is aimed to evaluate the effectiveness of intranasal and intraoral PBM administrations in management of anosmia and ageusia respectively. Twenty Caucasian subjects who diagnosed with anosmia and ageusia were recruited. Visual analogue scale was utilised to evaluate patients' self-reported for both olfactory and gustatory functionality. The laser-PBM parameters and treatment protocols for anosmia and ageusia were as follows respectively: 660 nm, 100 mW, two points intranasally, 60 J/session, 12 sessions; dual wavelengths (660 nm and 808 nm), 100 mW, three points intraorally, 216 J/session, 12 sessions. Our results showed a significant functionality improvement of both olfactory and gustatory functionality. Extensive studies with large data and long-term follow-up period are warranted.

Loss of Sour Taste Is the Striking Feature among Four Basic Taste Qualities in Tunisian COVID-19 Patients.

BACKGROUND: Taste disorders (TDs) have been reported to be very common in patients suffering from coronavirus disease 2019 (COVID-19), which is caused by the SARS-CoV-2 virus. In most of the hitherto conducted studies, a gustatory assessment was performed on the basis of surveys or self-reports by patients. The aim of our study was to undertake an objective assessment of four basic taste qualities by conducting tasting sessions that allowed detection thresholds in COVID-19 Tunisian patients and to study their associations with inflammation. METHODS: This analytical cross-sectional study was conducted on 89 patients aged between 21 to 70 years who had been diagnosed with COVID-19. We used Burghart taste strips to assess taste perception of the four taste qualities, i.e., sour, bitter, sweet, and salty. Serum levels of interleukin-1ß (IL-1ß), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and C-reactive protein (CRP) were measured. RESULTS: Taste disorders were reported by 40.4% of the patients, while objective assessments revealed that 63.8% of participants were suffering from hypogeusia and/or ageusia. Sour taste was the most altered (70.8%) gustatory quality. Patients with severe COVID-19 had significantly lower sour and bitter taste scores when compared to patients with minor/moderate forms. There was no significant association between serum inflammatory markers and taste disorders. However, the relationship between bitter and sweet taste qualities and IL-1ß levels was significant (p = 0.018 and p = 0.041). CONCLUSIONS: Our results demonstrate the interest in the objective assessment of taste dysfunctions in COVID-19 patients.

Sudden loss of smell and taste: clinical predictors of coronavirus disease 2019 infection.

OBJECTIVES: This study aimed: to evaluate the association between coronavirus disease 2019 infection and olfactory and taste dysfunction in patients presenting to the out-patient department with influenza-like illness, who underwent reverse transcription polymerase chain reaction testing for coronavirus; and to determine the sensitivity, specificity, and positive and negative predictive values of olfactory and taste dysfunction and other symptoms in these patients. METHODS: Patients presenting with influenza-like illness to the study centre in September 2020 were included in the study. The symptoms of patients who tested positive for coronavirus on reverse transcription polymerase chain reaction testing were compared to those with negative test results. RESULTS: During the study period, 909 patients, aged 12-70 years, presented with influenza-like illness; of these, 316 (34.8 per cent) tested positive for coronavirus. Only the symptoms of olfactory and taste dysfunction were statistically more significant in patients testing positive for coronavirus than those testing negative. CONCLUSION: During the pandemic, patients presenting to the out-patient department with sudden loss of sense of smell or taste may be considered as positive for coronavirus disease 2019, until proven otherwise.

Impairment of olfactory and gustatory sensations in severe acute respiratory syndrome corona virus 2 (SARS-CoV-2 virus) disease.

Severe acute respiratory syndrome corona virus 2 (SARS-CoV-2 virus) disease had first appeared in December 2019 in Wuhan, China, and since then, it has emerged as a global threat to humanity. An early diagnosis and isolation are the most significant measures required to prevent its spread. Recent anecdotal evidence has suggested impairment of olfactory and gustatory sensations associated with corona virus disease (COVID-19). Angiotensin-converting enzyme-2 is an important aspect for the manifestations seen in this deadly viral disease. The associated olfactory and gustatory dysfunction can also lead to partial and/or complete loss of the ability to smell and taste in the early stages of disease onset. Evidence has also suggested that the presence of SARS-CoV-2 nucleic acid in human saliva makes it the carrier of the infectious viral disease and aids in its diagnosis. The present review focuses on the listed clinical manifestations in the form of olfactory and gustatory impairment in SARS-CoV-2 virus disease.

Long-term follow-up of olfactory and gustatory dysfunction in COVID-19: 6 months case-control study of health workers.

PURPOSE: The study aimed to determine the incidence and long-term evolution of COVID-related olfactory (OD) and gustatory (GD) dysfunction, the recovery timeline, and the association with other symptoms. The secondary objective was to identify the predictive clinical factors for the evolution of these symptoms. METHODS: A prospective case-control study was conducted from March 15 to October 15, 2020, in health workers with COVID-19 related symptoms in a tertiary care hospital. 320 patients were included after 6 months of follow-up: 195 in the case group and 125 in the control group. Olfactory dysfunction (OD), dysosmia, and gustatory dysfunction (GD) onset and recovery rate after 6 months follow-up are analyzed in both groups. RESULTS: There were 125 (64.1%) in case group patients with OD and 118 (60.5%) with GD. Total or partial recovery OD and GD was found in 89%, mainly in the first 2 months. In the control group, there were 14 (11.2%) patients with OD and 33 (26.4%) patients with GD, with 100% of total/partial recovery. CONCLUSION: In both groups, OD and GD showed high-resolution rates during the first two months after the onset of symptoms. Nevertheless, 11% of the case group patients did not show any recovery, and the partial resolution was present in 30% of our patients, at the 6 months follow-up. We found a high correlation between OD and GD, both in the appearance of symptoms and in their recovery. Nasal obstruction and dyspnea have been identified as risk factors for the persistence of symptoms.