Olfactory training in long COVID-19 patients with lasting symptoms including olfactory dysfunction

INTRODUCTION. Two-thirds of patients with COVID-19 developed smell and taste dysfunction, of whom half experienced improvement within the first month. After six months, 5-15% still suffered from significant olfactory dysfunction (OD). Before COVID-19, olfactory training (OT) was proved to be effective in patients with post-infectious OD. Therefore, the present study aimed to investigate the progress of olfactory recovery with and without OT in patients with long COVID-19. METHODS. Consecutive patients with long COVID-19 referred to the Flavour Clinic at Godstrup Regional Hospital, Denmark, were enrolled. The diagnostic set-up at the first visit and follow-up included smell and taste tests, questionnaires, ENT examination and instructions in OT. RESULTS. From January 2021 to April 2022, 52 patients were included due to long COVID-19-related OD. The majority of patients complained of distorted sensory quality, in particular, parosmia. Two-thirds of the patients reported a subjective improvement of their sense of smell and taste along with a significant decline in the negative impact on quality of life (p = 0.0001). Retesting at follow-up demonstrated a significant increase in smell scores (p = 0.023) where a minimal clinically important difference (MCID) in smell scores was found in 23% of patients. Full training compliance was significantly associated with the probability of MCID improvement (OR = 8.13;p = 0.04). CONCLUSIONS. The average effect of OT is modest;however, full training compliance was significantly associated with an increased probability of a clinically relevant olfactory improvement. FUNDING. none. TRIAL REGISTRATION. not relevant.Copyright © 2023, Almindelige Danske Laegeforening. All rights reserved.

Recovery rates and parosmia in olfactory loss during the COVID-19 era

INTRODUCTION. Olfactory dysfunction (OD) is a common symptom of COVID-19. In some patients, OD persists for many months, fluctuates during recovery or parosmia may occur. Knowledge about the prognosis of these patients is insufficient. METHODS. Data on chemosensory function and possible prognostic factors were collected through a baseline questionnaire and six follow-up questionnaires answered at 2-3-month intervals. RESULTS. One year after onset of OD, 42.0% of the respondents reported sustained complete recovery, 41.7% reported partial recovery and 2.4% reported no improvement of olfaction. Follow-up was unavailable for 13.9%. Parosmia, high severity of OD and female sex were associated with lower rates of recovery. Subjects who reported that OD had a high impact on their quality of life were less likely to recover within one month. Smoking, alcohol habits, BMI and physical activity were not associated with persistence of OD. CONCLUSIONS. High recovery rates were reported within the first months. Recovery of sensory function after more than six months with no prior improvement was reported. After one year, 97.1% of participants with at least one year of follow-up had reported at least some recovery. Recurring OD after initial complete recovery was reported by 24.5% of participants. Parosmia and severity of OD were associated with prolonged recovery rates. FUNDING. AF received research funding from Velux Fonden. The sponsors had no say nor any responsibilities in relation to the study.

Frequent reversible causes to deteriorised or lost olfactory or gustatory function

Change in olfactory and/or gustatory dysfunction have gained attention in recent years because of COVID-19. However, these symptoms are common and have numerous different aetiologies, which should not be forgotten. Adequate diagnostic work up and clinical examination is essential. Treatment may include olfactory training, topically applied steroids and perhaps surgery. This review summarises common reversible causes of olfactory and/or gustatory dysfunction and current treatment modalities.

Frequent reversible causes to deteriorised or lost olfactory or gustatory function.

Change in olfactory and/or gustatory dysfunction have gained attention in recent years because of COVID-19. However, these symptoms are common and have numerous different aetiologies, which should not be forgotten. Adequate diagnostic work up and clinical examination is essential. Treatment may include olfactory training, topically applied steroids and perhaps surgery. This review summarises common reversible causes of olfactory and/or gustatory dysfunction and current treatment modalities.

Recovery rates and parosmia in olfactory loss during the COVID-19 era

INTRODUCTION: Olfactory dysfunction (OD) is a common symptom of COVID-19. In some patients, OD persists for many months, fluctuates during recovery or parosmia may occur. Knowledge about the prognosis of these patients is insufficient. METHODS: Data on chemosensory function and possible prognostic factors were collected through a baseline questionnaire and six follow-up questionnaires answered at 2-3-month intervals. RESULTS: One year after onset of OD, 42.0% of the respondents reported sustained complete recovery, 41.7% reported partial recovery and 2.4% reported no improvement of olfaction. Follow-up was unavailable for 13.9%. Parosmia, high severity of OD and female sex were associated with lower rates of recovery. Subjects who reported that OD had a high impact on their quality of life were less likely to recover within one month. Smoking, alcohol habits, BMI and physical activity were not associated with persistence of OD. CONCLUSIONS: High recovery rates were reported within the first months. Recovery of sensory function after more than six months with no prior improvement was reported. After one year, 97.1% of participants with at least one year of follow-up had reported at least some recovery. Recurring OD after initial complete recovery was reported by 24.5% of participants. Parosmia and severity of OD were associated with prolonged recovery rates. FUNDING: AF received research funding from Velux Fonden. The sponsors had no say nor any responsibilities in relation to the study. TRIAL REGISTRATION: not relevant. Articles published in the DMJ are “open access”. This means that the articles are distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits any non-commercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.

Republication de : Incidence and duration of self-reported hearing loss and tinnitus in a cohort of COVID-19 patients with sudden chemosensory loss: A STROBE observational study

Aims To investigate the self-reported audiological symptoms in a cohort of coronavirus disease 2019 (COVID-19) patients and monitor improvement or recovery. Material and methods Following the STROBE guidelines for observational studies, a retrospective questionnaire concerning audio-vestibular symptoms was conducted in a cohort of Danish COVID-19 patients with self reported chemosensory loss. Data regarding demographics, symptoms onset, duration and remission was registered in a REDCap database. Results Of the 225 respondents with chemosensory loss, 59 (26.2%) reported concomitant hearing loss (10.7%) or tinnitus (16.4%). In a follow-up questionnaire focused on ear-symptoms, severity, and duration (n=31), 17 reported hearing loss and 21 reported tinnitus. Debut of hearing loss and tinnitus were on average 10 and 30 days respectively, after onset of initial symptoms. Among the hearing loss patients, only two patients experienced full recovery, whereas 15 had partial or no recovery after on average 266 days from COVID-19 symptom onset. Among the tinnitus patients, 7/21 had full recovery, while 14 had partial or no recovery after on average 259 days from COVID-19 symptom onset. Conclusion In a large Danish cohort of COVID-19 patients, a significant proportion experienced concomitant audiological symptoms which seem long lasting and with negative impact on quality of life. This study warrants further investigation of the association between COVID-19 and audio-vestibular symptoms, and the need for rehabilitation among convalescents.

Incidence and duration of self-reported hearing loss and tinnitus in a cohort of COVID-19 patients with sudden chemosensory loss: A STROBE observational study.

AIMS: To investigate the self-reported audiological symptoms in a cohort of coronavirus disease 2019 (COVID-19) patients and monitor improvement or recovery. MATERIAL AND METHODS: Following the STROBE guidelines for observational studies, a retrospective questionnaire concerning audio-vestibular symptoms was conducted in a cohort of Danish COVID-19 patients with self reported chemosensory loss. Data regarding demographics, symptoms onset, duration and remission was registered in a REDCap database. RESULTS: Of the 225 respondents with chemosensory loss, 59 (26.2%) reported concomitant hearing loss (10.7%) or tinnitus (16.4%). In a follow-up questionnaire focused on ear-symptoms, severity, and duration (n=31), 17 reported hearing loss and 21 reported tinnitus. Debut of hearing loss and tinnitus were on average 10 and 30 days respectively, after onset of initial symptoms. Among the hearing loss patients, only two patients experienced full recovery, whereas 15 had partial or no recovery after on average 266 days from COVID-19 symptom onset. Among the tinnitus patients, 7/21 had full recovery, while 14 had partial or no recovery after on average 259 days from COVID-19 symptom onset. CONCLUSION: In a large Danish cohort of COVID-19 patients, a significant proportion experienced concomitant audiological symptoms which seem long lasting and with negative impact on quality of life. This study warrants further investigation of the association between COVID-19 and audio-vestibular symptoms, and the need for rehabilitation among convalescents.

[Taste and smell loss in patients with COVID-19]

In the aftermath of COVID-19, the association between SARS-CoV-2 and chemosensory deficits have been well established. Taste and smell loss have been included in the official lists of symptoms worldwide, as it is a common symptom (and for some patients the only symptom) of COVID-19 as described in this review. Patients with COVID-19 often have combined taste and smell loss, have a milder clinical presentation, and are younger than previous patients with postviral olfactory loss. Patients should start olfactory training early and should be seen by an ear, nose and throat physician if they do not experience improvement of the senses within 12 weeks.

Prolonged complaint s of chemosensory loss aft er covid-19

Introduction: Chemosensory loss is a common symptom of coronavirus disease 2019 (COVID-19) and has been associated with a milder clinical course in younger patients. Whereas several studies have confirmed this association, knowledge about the improvement and recovery of olfactory and gustatory loss is lacking. The aim of this study was to investigate the temporal dynamics of improvement and recovery from sudden olfactory and gustatory loss in patients with confirmed and suspected COVID-19. Methods: Subjective chemosensory function, symptoms of COVID-19, COVID-19 tests results, demographics and medical history were collected through a questionnaire. Results: Among the 109 study participants, 95 had a combined olfactory and gustatory loss, five participants had isolated olfactory loss and nine participants has isolated taste loss. The mean age of participants was 39.4 years and 25% of participants were under the age of 30 years. Young age was not associated with a higher recovery rate. After a mean time of > 30 days since the chemosensory loss, participants reported relatively low recovery and improvement rates. For participants with olfactory loss, only 44% had fully recovered, whereas 28% had not yet experienced any improvement of symptoms. After gustatory loss, 50% had fully recovered, whereas 20% had not yet experienced any improvement. Olfactory and gustatory deficits were predominantly quantitative and mainly included complete loss of both olfactory and gustatory function. Conclusions: Chemosensory loss was frequent in young individuals and persisted beyond a month after symptom onset, often without any improvement during this time. Funding: The author wishes to acknowledge research salary funding from Arla Foods (Viby, Denmark) and the Central Region Denmark. The sponsors had no say, roles or responsibilities in relation to the study, including (but not limited to) the study design, data collection, management and analysis. Trial registration: not relevant.