Recovery From COVID-19-Related Olfactory Disorders and Quality of Life: Insights From an Observational Online Study

Seawater nasal wash to reduce symptom duration and viral load in COVID-19 and upper respiratory tract infections: a randomized controlled multicenter trial

PURPOSE

The objective was to assess the efficacy of seawater nasal wash on symptom duration, intranasal viral load, household transmission in COVID-19 and URTIs.

METHODS

This prospective, randomized, controlled, multicentric, parallel study included 355 mild/moderate COVID-19 and URTI adults with rhinologic symptoms ≤ 48h. Active group performed 4-daily nasal washes with undiluted isotonic seawater versus control group (without nasal wash). Symptoms were self-assessed daily using the WURSS-21 questionnaire for 3 weeks. Viral load was measured by RT-PCR on nasopharyngeal swabs collected on Day 0, Day 5, Day 14 and Day 21. Digital droplet PCR was additionally performed for SARS-CoV-2.

RESULTS

Overall COVID-19 subjects recovered earlier the ability to accomplish daily activities in the active group (- 1.6 day, p = 0.0487) with earlier improvement of taste (- 2 days, p = 0.0404). COVID-19 subjects with severe nasal symptoms at D0 showed the earliest resolution of anosmia (- 5.2 days, p = 0.0281), post-nasal drip (- 4.1 days, p = 0.0102), face pain/heaviness (- 4.5 days, p = 0.0078), headache (- 3.1 days, p = 0.0195), sore throat (- 3.3 days, p = 0.0319), dyspnea (- 3.1 days, p = 0.0195), chest congestion (- 2.8 days, p = 0.0386) and loss of appetite (- 4.5 days, p = 0.0186) with nasal wash. In URTIs subjects, an earlier resolution of rhinorrhea (- 3.5 days, p = 0.0370), post-nasal drip (- 3.7 days, p = 0.0378), and overall sickness (- 4.3 days, p = 0.0248) was reported with nasal wash. Evolution towards more severe COVID-19 was lower in active vs control, with earlier viral load reduction in youngest subjects (≥ 1.5log10 copies/10000 cells at Day 5: 88.9% vs 62.5%, p = 0.0456). In the active group, a lower percentage of SARS-CoV-2 positive household contacts (0-10.7%) was reported vs controls (3.2-16.1%) among subjects with Delta variant (p = 0.0413).

CONCLUSION

This trial showed the efficacy and safety of seawater nasal wash in COVID-19 and URTIs.

TRIAL REGISTRATION

Trial registry ClinicalTrials.gov: NCT04916639. Registration date: 04.06.2021.

Identification of the needs of individuals affected by COVID-19

BACKGROUND

The optimal management of COVID-19 symptoms and their sequelae remains an important area of clinical research. Policy makers have little scientific data regarding the effects on the daily life of affected individuals and the identification of their needs. Such data are needed to inform effective care policy.

METHODS

We studied 639 people with COVID-19 resident in France via an online questionnaire. They reported their symptoms, effects on daily life, and resulting needs, with particular focus on olfaction.

RESULTS

The results indicate that a majority of participants viewed their symptoms as disabling, with symptoms affecting their physical and mental health, social and professional lives. 60% of the individuals reported having unmet medical, psychological and socio-professional support needs. Finally, affected individuals were concerned about the risk and invasiveness of possible treatments as shown by a preference for non-invasive intervention over surgery to cure anosmia.

CONCLUSIONS

It is important that policy makers take these needs into consideration in order to assist affected individuals to regain a normal quality of life.

A data set of symptoms and needs of individuals affected by COVID-19

Here we provide data from an online survey of 639 people diagnosed with COVID-19 and resident in France, who were diagnosed with COVID-19 between 30th Jan 2020 and 29th August 2022. In addition to demographic information the survey includes questions about participants' symptoms (by category), symptom onset and persistence, and the effects these symptoms had on their daily lives. Participants were able to include information related to their perceived medical, social and professional needs. These data are needed in order to create effective care policies addressing post-COVID sequelae. Information related to symptom association & dynamics is expected to be useful to clinicians and may also inform more fundamental studies.

The assessment of qualitative olfactory dysfunction in COVID-19 patients: a systematic review of tools and their content validity

Background

There is a lack of overview of the tools used to assess qualitative olfactory dysfunction, including parosmia and phantosmia, following COVID-19 illness. This could have an impact on the diagnosis and treatment offered to patients. Additionally, the formulations of symptoms are inconsistent and often unclear, and consensus around the wording of questions and responses is needed.

Aim of study

The aim of this systematic review is to provide an overview of tools used to assess qualitative olfactory dysfunction after COVID-19, in addition to addressing the content validity (i.e., item and response formulations) of these tools.

Methods

MEDLINE, Web of Science, and EMBASE were searched 5th of August 2022 and updated on the 25th of April 2023 to identify studies that assess qualitative olfactory dysfunction in COVID-19 patients. Primary outcomes were the tool used (i.e., questionnaire or objective test) and item and response formulations. Secondary outcomes included psychometric properties, study design, and demographic variables.

Results

The assessment of qualitative olfactory dysfunction is characterized by heterogeneity, inconsistency, and lack of validated tools to determine the presence and degree of symptoms. Several tools with overlapping and distinct features were identified in this review, of which some were thorough and detailed, while others were merely assessing the presence of symptoms as a binary measure. Item and response formulations are also inconsistent and often used interchangeably, which may lead to confusion, incorrect diagnoses, and inappropriate methods for solving the problem.

Conclusions

There is an unmet need for a reliable and validated tool for assessing qualitative olfactory dysfunction, preferably one that also captures quantitative olfactory issues (i.e., loss of smell), to ensure time-effective and specific assessment of the ability to smell. A consensus around the formulation of items and response options is also important to increase the understanding of the problem, both for clinicians, researchers, and the patient, and ultimately to provide the appropriate diagnosis and treatment.

Registration and protocol

The URL is https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=351621. A preregistered protocol was submitted and accepted (12.09.22) in the International prospective register of systematic reviews (PROSPERO) with the registration number CRD42022351621.

Food-related experiences and behavioral responses among people affected by chemosensory dysfunctions following COVID-19: A scoping review

A category of symptoms that became characteristic early in the first wave of the coronavirus disease 2019 (COVID-19) pandemic was chemosensory dysfunctions (alterations of smell and taste). Such symptoms substantially affect food and eating-cornerstones for both nutrition-related health outcomes and for quality of life. Based on this, this scoping review aimed to map out existing scientific literature on food-related experiences and related behavioral responses among people affected by chemosensory dysfunctions following COVID-19. A librarian-supported search of PsycInfo, PubMed, and Scopus for publications written in English (2020 to April 26, 2022) was conducted. Two authors searched for and screened publications and three others extracted and collated data. These are reported following the Preferred Reporting Items of Systematic reviews and Meta-Analyses extension for Scoping Reviews. Of 1169 hits, 9 publications were included in the review. The results are thematized as "Psychological and social aspects" and "Nutritional aspects," each with the subsections "Experiences" and "Behavioral responses." A great variety of food-related problems, nutritional and mental health effects, and implications for social life are identified. People affected by chemosensory dysfunctions following COVID-19 suffer, as evident both in stories from qualitative studies and in measurements of quality of life. The results impact all professions who are and may come to be involved in treating these patients, such as nurses, physicians, dietitians, and psychologists. With more knowledge about the dysfunctions' manifestation, duration, and impact on everyday life, multiprofessional teams need to collaborate in supporting patients medically, psychosocially, and nutritionally.

The Correlation between the Results of the Sniffin' Sticks Test, Demographic Data, and Questionnaire of Olfactory Disorders in a Hungarian Population after a SARS-CoV-2 Infection

BACKGROUND

After a severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, smell disorders frequently occur, significantly affecting patients' quality of life (QoL).

METHODS

110 patients with persistent olfactory disorder after coronavirus infection were enrolled. These patients underwent chemosensory testing using the Sniffin' Sticks test, and completed the Questionnaire of Olfactory Disorders (QOD).

RESULTS

30% of the patients reported anosmia, and 70% reported hyposmia. Upon comparing subjective and chemosensory testing categories, good category matching was observed in 75.3% (i.e., anosmia based on both methods in 10 and hyposmia in 48 cases). Statistical analysis using the Chi-square test revealed a significant result (p = 0.001 *). Between the TDI (i.e., Threshold, Discrimination, Identification) results of the three subjective report groups (i.e., hyposmia, anosmia, and parosmia), no significant differences were observed. When the TDI and QOD results were compared, no consistent significant correlations were found in most TDI and QOD outcomes. Between the TDI and Scale 2 results, a significant, although slight correlation was observed by the Spearman's (rho = 0.213, p = 0.027 *) and Pearson's (rho = 0.201, p = 0.037 *) tests.

CONCLUSIONS

The nonsignificant correlation between objective and subjective methods suggests that these results should be interpreted independently. Moreover, adequate management is essential even in mild cases.

Qualitative Olfactory Dysfunction and COVID-19: An Evidence-Based Review with Recommendations for the Clinician

BACKGROUND

Nearly 40% of patients who experience smell loss during SARS-CoV-2 infection may develop qualitative olfactory dysfunction, most commonly parosmia. Our evidence-based review summarizes the evolving literature and offers recommendations for the clinician on the management of patients experiencing parosmia associated with COVID-19.

METHODS

We performed a systematic search using independent queries in PubMed, Embase, Ovid, and Cochrane databases, then categorized articles according to themes that emerged regarding epidemiology, effect on quality of life, disease progression, prognosis, pathophysiology, diagnosis, and treatment of parosmia.

RESULTS

We identified 123 unique references meeting eligibility and performed title and abstract review with 2 independent reviewers, with 74 articles undergoing full-text review. An inductive approach to thematic development provided 7 central themes regarding qualitative olfactory dysfunction following COVID-19.

CONCLUSIONS

While other respiratory viruses are known to cause qualitative olfactory disturbances, the incidence of parosmia following COVID-19 is notable, and correlates negatively with age. The presence of parosmia predicts persistent quantitative olfactory dysfunction. Onset can occur months after infection, and symptoms may persist for well over 7 months. Affected patients report increased anxiety and decreased quality of life. Structured olfactory training with essential oils is the preferred treatment, where parosmia predicts recovery of aspects of quantitative smell loss when undergoing training. There is limited evidence that nasal corticosteroids may accelerate recovery of olfactory function. Patients should be prepared for the possibility that symptoms may persist for years, and providers should guide them to resources for coping with their psychosocial burden.

Impact of Hedonics and Magnitude Upon Validated Psychophysical Olfactory Tests and Olfactory-Specific Quality of Life

Introduction

Patients often describe the olfactory loss as either the inability to detect unpleasant odors (eg, smoke or spoiled food) or noticeable impairment in enjoying pleasant odors (eg, food and fragrances). This complex relationship between the hedonics of various odors, their perceived magnitude in odor strength, and the impact on patient quality of life is not well understood.

Methods

Sixty-five subjects underwent testing with the Henkin olfaction test which assesses hedonics and magnitude for odors traditionally deemed unpleasant (pyridine/dead fish and thiophene/gasoline) and pleasant (amyl acetate/banana and nitrobenzene/almond). Subjects also completed Smell Identification Test-40 (SIT-40), Sniffin’ Sticks (Sniffin’ Sticks), and Snap & Sniffin’ Sticks (Snap) Olfactory Tests, as well as the 17-item Questionnaire for Olfactory Disorders Negative Statements (QODNS) and olfactory symptom visual analog scale (VAS). Spearman's rank correlations were conducted between various olfactory domains, QODNS and VAS.

Results

Mean age was 52.1 years (range: 28-86), with 63.1% females. Magnitude estimation was greatest for pyridine. Most people rated thiophene (75.4%) and pyridine (92.3%) as “unpleasant.” Although most people rated amyl acetate (47.7%) and nitrobenzene (56.9%) as “pleasant,” many rated amyl acetate (52.3%) and nitrobenzene (43.1%) as “neutral” or “unpleasant” scents. Hedonics for unpleasant odors correlated with each other ( rs = 0.60), but not with hedonics for pleasant odors. Hedonics for unpleasant odors also correlated with magnitude estimation and other psychophysical tests. These findings were not seen for hedonics of pleasant odors.

Conclusions

The use of unpleasant odors in Henkin testing showed unique relationship patterns with patient-reported outcome measures and validated olfactory tests, which may provide utility in characterizing olfactory dysfunction. The incorporation of more unpleasant odors in current psychophysical olfactory testing may provide enhanced information regarding the patient impact of olfactory dysfunction.

Phantom smells: a prevalent COVID-19 symptom that progressively sets in

PURPOSE

One of the long-term symptoms of COVID-19 is phantosmia, a type of Olfactory Disorder (OD) that has deleterious impacts on patients' quality of life. The aim of this article was to study how this poorly understood qualitative OD manifests itself in the COVID-19.

METHODS

4691 patients with COVID-19 responded to our online questionnaire focusing on COVID-19-related OD. We first analyzed the prevalence of phantosmia in this population. Then, with the help of Natural Language Processing techniques, we investigated the qualitative descriptions of phantom smells by the 1723 respondents who reported phantosmia.

RESULTS

The prevalence of phantosmia was of 37%. Women were more likely to report phantosmia than men, as well as respondents for whom OD was described as fluctuating rather than permanent, lasted longer, was partial rather than total and appeared progressively rather than suddenly. The relationship between OD duration and phantosmia followed a logarithmic function, with a prevalence of phantosmia increasing strongly during the first 2 months of the disease before reaching a plateau and no decrease over the 15 months considered in this study. Qualitative analyses of phantosmia descriptions with a sentiment analysis revealed that the descriptions were negatively valenced for 78% of the respondents. Reference to "tobacco" was more frequent in non-smokers. Source names and odor characteristics were used differently according to age and OD duration.

CONCLUSION

The results of this descriptive study of phantosmia contribute to the current efforts of the medical community to better understand and treat this rapidly increasing COVID-19-related OD.

Characterization, treatment modalities, and self-perceived improvement of post-COVID-19 phantosmia: a case series of eleven patients

Background: Loss of smell and taste is one of the early and sensitive symptoms of COVID-19 that usually improves over time. Post-COVID-19 phantosmia, a smell distorted sensation without the presence of odorants, has deleterious and long-lasting effects on the patient's quality of life. We aimed to present our experience with phantosmia. Case presentations: We report a description of a series of eleven cases (age of 29 ± 9 years, and 54.5% females) of post-COVID-19 phantosmia without any other comorbidity, and the effects of combined treatment modalities (olfactory training, nasal irrigation with budesonide and oral prednisolone) on self-perceived improvement in phantosmia. Conclusions: We postulate that the combined 10 days oral prednisolone, smell training, and nasal irrigation for three months improved post-COVID-19 phantosmia assessed as post vs. pre self-perceived improvement, although this was not aimed at as a treatment since it was not compared to untreated controls.

Your Money or Your Sense of Smell? A Comparative Analysis of the Sensory and Psychological Value of Olfaction

In public discourse, the sense of smell is typically characterized as the least important of the five senses. However, there are very little empirical data on this topic. Recently, much more attention has been brought to the sense of smell since olfactory dysfunction is a primary and often long-term symptom of COVID-19 infection. It was therefore of interest to expand research on the perceived value of olfaction in the current cultural condition. We developed a survey that directly compared the value of the senses of smell, hearing, and vision with each other and in relation to nine common items representing digital, material, personal, and physical commodities of varying social and emotional meaningfulness (phone, $10,000, favorite social media, online shopping, favorite streaming service, dream vacation, pet, hair, little left toe). In total, four hundred and seven female and male respondents comprising two life-stage groups (college students, general public adults) participated in our online survey study during winter–spring of 2021. The results reveal that the sense of smell was perceived as vastly less important than vision and hearing and much less valuable than various common commodities. We also found that life-stage and gender mediated our findings. For example, one-quarter of the college student respondents would give up their sense of smell in order to keep their phone and nearly half of all women would give up their sense of smell to keep their hair. Our data further illustrate that the senses of vision and hearing are valued relatively similarly. A number of questions arise from the present data and suggestions for ways in which our survey can be expanded and altered to address further research are discussed.