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Australian Journal of General Practice Apr 2022On average, 47% of patients with COVID-19 self-report an olfactory disorder, although the inaccuracy of self-reporting means this figure may be higher.
On average, 47% of patients with COVID-19 self-report an olfactory disorder, although the inaccuracy of self-reporting means this figure may be higher.
Topics: Anosmia; COVID-19; Humans; Olfaction Disorders; SARS-CoV-2
PubMed: 35393605
DOI: 10.31128/AJGP-COVID-51-3 -
European Archives of... Feb 2023Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is the causative agent of COVID-19 which was detected in late 2019 in Wuhan, China. As of September... (Review)
Review
Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is the causative agent of COVID-19 which was detected in late 2019 in Wuhan, China. As of September 2022, there have been over 612 million confirmed cases of COVID-19 with over 6.5 million associated deaths. In many cases, anosmia and dysgeusia have been identified as primary symptoms of COVID-19 infection in patients. While the loss of smell (anosmia) and loss of taste (dysgeusia) due to COVID-19 infection is transient in most patients, many report that these symptoms persist following recovery. Understanding the pathogenesis of these symptoms is paramount to early treatment of the infection. We conducted a literature review of Google Scholar and PubMed to find and analyze studies discussing anosmia and dysgeusia in the context of COVID-19 to understand the progression and management of these symptoms. The mechanism for dysgeusia is largely unknown; however, pathogenesis of anosmia includes inflammation and cytokine release resulting from the infection that alters neuronal signaling, thus inducing the loss of smell that patients experience. Anosmia may be managed and potentially resolved sooner with a combination therapy of olfactory training and budesonide irrigation of the nasal cavity. It is important to note that the variants of SARS-CoV-2 are genetically distinguished from the original virion due to a mutation in their spike proteins, giving them a different symptom profile regarding anosmia and dysgeusia. This variability in symptomatology is an area of study that needs to be further explored.
Topics: Humans; COVID-19; Dysgeusia; Anosmia; SARS-CoV-2; Pandemics; Olfaction Disorders
PubMed: 36209486
DOI: 10.1007/s00405-022-07689-w -
Journal of Neurovirology Apr 2022COVID-19 pandemic spreads worldwide, with more than 100 million positive cases and more than 2 million deaths. From the beginning of the COVID-19 pandemic, several... (Review)
Review
COVID-19 pandemic spreads worldwide, with more than 100 million positive cases and more than 2 million deaths. From the beginning of the COVID-19 pandemic, several otolaryngologists described many cases of a sudden loss of smell (anosmia) associated with the disease with or without additional symptoms. Anosmia is often the first and sometimes the only sign in the asymptomatic carriers of COVID-19. Still, this disorder is underestimated, and it is not life-threatening. However, it significantly decreases the quality of life. This olfactory dysfunction continues in several cases even after the nasopharyngeal swab was negative. The occurrence of anosmia can be used as a screening tool for COVID-19 patients and can be used to identify these patients to accomplish the isolation and tracking procedures. In this review, we highlighted the possible mechanisms of anosmia in COVID-19 patients, major pathologies and features of anosmia, implications of anosmia in early diagnosis of COVID-19, evaluation of the smell function during COVID-19, and management and treatment options of COVID-19 anosmia.
Topics: Anosmia; COVID-19; Humans; Olfaction Disorders; Pandemics; Quality of Life; SARS-CoV-2
PubMed: 35249186
DOI: 10.1007/s13365-022-01060-9 -
British Dental Journal Aug 2020
Topics: Ageusia; Anosmia; COVID-19; Humans; SARS-CoV-2
PubMed: 32811912
DOI: 10.1038/s41415-020-2009-5 -
European Journal of Neurology Dec 2022Clinical outcomes of multiple sclerosis (MS) patients affected by coronavirus disease 2019 (COVID-19) have been thoroughly investigated, but a further analysis on main...
BACKGROUND AND PURPOSE
Clinical outcomes of multiple sclerosis (MS) patients affected by coronavirus disease 2019 (COVID-19) have been thoroughly investigated, but a further analysis on main signs and symptoms and their risk factors still needs attention. The objective of this study was to group together and describe based on similarity the most common signs and symptoms of COVID-19 in MS patients and identify all factors associated with their manifestation.
METHOD
Logistic and linear regression models were run to recognize factors associated with each pooled group of symptoms and their total number.
RESULTS
From March 2020 to November 2021, data were collected from 1354 MS patients with confirmed infection of COVID-19. Ageusia and anosmia was less frequent in older people (odds ratio [OR] 0.98; p = 0.005) and more in smoker patients (OR 1.39; p = 0.049). Smoke was also associated with an incremental number of symptoms (OR 1.24; p = 0.031), substance abuse (drugs or alcohol), conjunctivitis and rash (OR 5.20; p = 0.042) and the presence of at least one comorbidity with shortness of breath, tachycardia or chest pain (OR 1.24; p = 0.008). Some disease-modifying therapies were associated with greater frequencies of certain COVID-19 symptoms (association between anti-CD20 therapies and increment in the number of concomitant symptoms: OR 1.29; p = 0.05). Differences in frequencies between the three waves were found for flu-like symptoms (G1, p = 0.024), joint or muscle pain (G2, p = 0.013) and ageusia and anosmia (G5, p < 0.001). All cases should be referred to variants up to Delta.
CONCLUSION
Several factors along with the choice of specific therapeutic approaches might have a different impact on the occurrence of some COVID-19 symptoms.
Topics: Humans; Aged; COVID-19; Ageusia; SARS-CoV-2; Anosmia; Multiple Sclerosis
PubMed: 36086905
DOI: 10.1111/ene.15554 -
Current Opinion in Allergy and Clinical... Jun 2021Olfactory dysfunction (OD) can be a single and early prominent symptom of severe acute respiratory syndrome (SARS)-COV-2 infection unlike middle east respiratory... (Review)
Review
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.
Topics: Anosmia; COVID-19; Humans; Middle East Respiratory Syndrome Coronavirus; SARS-CoV-2; Taste Disorders
PubMed: 33560742
DOI: 10.1097/ACI.0000000000000735 -
Journal of Neurovirology Feb 2023Clinical manifestations of human coronavirus (HCoV)-related diseases are mostly related to the respiratory system, although secondary complications such as headache,...
Clinical manifestations of human coronavirus (HCoV)-related diseases are mostly related to the respiratory system, although secondary complications such as headache, anosmia, ageusia, and myalgia have been reported. HCoV infection and replication in chemosensory cells associated with ageusia and anosmia is poorly understood. Here, we characterized HCoV-OC43 and SARS-CoV-2 infection in two types of chemosensory cells, olfactory and taste cells, with their unique molecular and histological characteristics. We first assessed HCoV-OC43 infection in in vitro cultured human olfactory epithelial cells (hOECs) and fungiform taste papilla (HBO) cells. Interestingly, while both cell types were susceptible to HCoV-OC43 infection, viral replication rates were significantly reduced in HBO cells compared to hOECs. More interestingly, while culture media from hOECs was able to produce secondary infection in Vero cells, there was very limited secondary infection from HBO cells, suggesting that HBO cells may not be able to release infectious virus. On the other hand, unlike HCoV-OC43, SARS-CoV-2 showed comparable levels of viral infection rates in both hOECs and HBO cells. Furthermore, our RT-qPCR-based gene array studies revealed that several key genes involved in taste and olfactory functions were significantly altered by SARS-CoV-2 infection. These results may suggest a possible mechanism associated with chemosensory symptoms, such as anosmia and ageusia in patients infected with SARS-CoV-2.
Topics: Animals; Chlorocebus aethiops; Humans; COVID-19; Vero Cells; Ageusia; Anosmia; Coinfection; SARS-CoV-2; Coronavirus OC43, Human
PubMed: 36719595
DOI: 10.1007/s13365-023-01117-3 -
AJNR. American Journal of Neuroradiology Jan 2021
Topics: Anosmia; COVID-19; Humans; Magnetic Resonance Imaging; Olfactory Bulb; SARS-CoV-2
PubMed: 33272952
DOI: 10.3174/ajnr.A6943 -
Otolaryngology--head and Neck Surgery :... Jun 2021This study aimed to investigate the differences in olfactory cleft (OC) morphology in coronavirus disease 2019 (COVID-19) anosmia compared to control subjects and...
OBJECTIVE
This study aimed to investigate the differences in olfactory cleft (OC) morphology in coronavirus disease 2019 (COVID-19) anosmia compared to control subjects and postviral anosmia related to infection other than severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
STUDY DESIGN
Prospective.
SETTING
This study comprises 91 cases, including 24 cases with anosmia due to SARS-CoV-2, 38 patients with olfactory dysfunction (OD) due to viral infection other than SARS-CoV-2, and a control group of 29 normosmic cases.
METHODS
All cases had paranasal sinus computed tomography (CT), and cases with OD had magnetic resonance imaging (MRI) dedicated to the olfactory nerve. The OC width and volumes were measured on CT, and T2-weighted signal intensity (SI), olfactory bulb volumes, and olfactory sulcus depths were assessed on MRI.
RESULTS
This study showed 3 major findings: the right and left OC widths were significantly wider in anosmic patients due to SARS-CoV-2 (group 1) or OD due to non-SARS-CoV-2 viral infection (group 2) when compared to healthy controls. OC volumes were significantly higher in group 1 or 2 than in healthy controls, and T2 SI of OC area was higher in groups 1 and 2 than in healthy controls. There was no significant difference in olfactory bulb volumes and olfactory sulcus depths on MRI among groups 1 and 2.
CONCLUSION
In this study, patients with COVID-19 anosmia had higher OC widths and volumes compared to control subjects. In addition, there was higher T2 SI of the olfactory bulb in COVID-19 anosmia compared to control subjects, suggesting underlying inflammatory changes. There was a significant negative correlation between these morphological findings and threshold discrimination identification scores.
LEVEL OF EVIDENCE
Level 4.
Topics: Adult; Anosmia; COVID-19; Case-Control Studies; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Nasal Cavity; Olfactory Bulb; Olfactory Mucosa; Organ Size; Prospective Studies; Tomography, X-Ray Computed
PubMed: 33045908
DOI: 10.1177/0194599820965920 -
Current Topics in Medicinal Chemistry 2022The SARS-CoV-2 virus is responsible for COVID-19 affecting millions of humans around the world. COVID-19 shows various clinical symptoms (fever, cough, fatigue,... (Review)
Review
The SARS-CoV-2 virus is responsible for COVID-19 affecting millions of humans around the world. COVID-19 shows various clinical symptoms (fever, cough, fatigue, diarrhea, body aches, headaches, anosmia, and hyposmia). Approximately 30% of patients with COVID-19 showed neurological symptoms, from mild to severe manifestations including headache, dizziness, impaired consciousness, encephalopathy, anosmia, hypogeusia, and hyposmia, among others. The neurotropism of the SARS-CoV-2 virus explains its neuroinvasion provoking neurological damage such as acute demyelination, neuroinflammation, etc. At the molecular level, the COVID-19 patients had higher levels of cytokines and chemokines known as cytokines storms which disrupt the blood-brain barrier allowing the entrance of monocytes and lymphocytes, causing neuroinflammation, neurodegeneration, and demyelination. In addition, the proinflammatory cytokines have been observed in ischemic, hemorrhagic strokes, seizures, and encephalopathy. In this sense, early neuroprotective management should be adopted to avoid or decrease neurological damage due to SARS-CoV-2 infection. Several approaches can be used; one of them includes using HDAC inhibitors (HDACi) due to their neuroprotective effects. Also, the HDACi down-regulates the proinflammatory cytokines (IL-6 and TNF-α) decreasing the neurotoxicity. HDACi can also avoid and prevent the entrance of the virus into the central nervous System (CNS) and decrease the virus replication by downregulating the virus receptors. Here we review the mechanisms that could explain how the SARS-CoV-2 virus could reach the CNS, induce neurological damage and symptoms, and the possibility to use HDACi as neuroprotective therapy.
Topics: Anosmia; Brain Diseases; Cytokines; Demyelinating Diseases; Humans; Nervous System Diseases; Neuroprotection; SARS-CoV-2; COVID-19 Drug Treatment
PubMed: 35240959
DOI: 10.2174/1568026622666220303113445