COVID-19-associated anosmia
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Moises Romo M.D.
Synonyms and keywords:
Overview
Anosmia has been formally recognized as a characteristic symtom of COVID-19 infection.[1]
Historical Perspective
[Disease name] was first discovered by [name of scientist], a [nationality + occupation], in [year]/during/following [event].
The association between [important risk factor/cause] and [disease name] was made in/during [year/event].
In [year], [scientist] was the first to discover the association between [risk factor] and the development of [disease name].
In [year], [gene] mutations were first implicated in the pathogenesis of [disease name].
There have been several outbreaks of [disease name], including -----.
In [year], [diagnostic test/therapy] was developed by [scientist] to treat/diagnose [disease name].
Classification
There is no established system for the classification of [disease name].
OR
[Disease name] may be classified according to [classification method] into [number] subtypes/groups: [group1], [group2], [group3], and [group4].
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[Disease name] may be classified into [large number > 6] subtypes based on [classification method 1], [classification method 2], and [classification method 3]. [Disease name] may be classified into several subtypes based on [classification method 1], [classification method 2], and [classification method 3].
OR
Based on the duration of symptoms, [disease name] may be classified as either acute or chronic.
OR
If the staging system involves specific and characteristic findings and features: According to the [staging system + reference], there are [number] stages of [malignancy name] based on the [finding1], [finding2], and [finding3]. Each stage is assigned a [letter/number1] and a [letter/number2] that designate the [feature1] and [feature2].
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The staging of [malignancy name] is based on the [staging system].
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There is no established system for the staging of [malignancy name].
Pathophysiology
- Now in day, more than 200 types of viruses are identified to cause anosmia; coronavirus strains are responsable of 10-15% of the cases.[1][2]
- Human strains of coronavirus (HCoVs) can infect and spread through the olfactory bulb.[3][1]
- The mechanism of central nervous system (CNS) invasion is unclear.[3]
- Studies suggest that viruses may propagate from the nasal cavity to the olfactory bulb through neuron-to-neuron axonal transport or passive diffusion of released viral particles.[3]
- A study from Germany described that approximately two thirds of confirmed COVID-19 infections presented anosmia and dysgeusia at some point of the disease.[4] Another study from South Korea, with 3191 mild-disease patients reported only 15.3% of anosmia or dysgeusia.[5]
- In a study, 74.4% reported complete loss of smell.[1]
- Anosmia may occur as the only symptom of COVID-19 in approximately 16% of individuals.[1]
- Anosmia occurs more commonly after the onset of other symptoms. In a study involving 1325 participants with anosmia (with no confirmatory COVID-19 test), 13% reported anosmia before their onset, 38.4% at the same time, and in 48.6% after the onset of symptoms.[1]
The exact pathogenesis of [disease name] is not fully understood.
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It is thought that [disease name] is the result of / is mediated by / is produced by / is caused by either [hypothesis 1], [hypothesis 2], or [hypothesis 3].
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[Pathogen name] is usually transmitted via the [transmission route] route to the human host.
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Following transmission/ingestion, the [pathogen] uses the [entry site] to invade the [cell name] cell.
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[Disease or malignancy name] arises from [cell name]s, which are [cell type] cells that are normally involved in [function of cells].
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The progression to [disease name] usually involves the [molecular pathway].
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The pathophysiology of [disease/malignancy] depends on the histological subtype.
Causes
Disease name] may be caused by [cause1], [cause2], or [cause3].
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Common causes of [disease] include [cause1], [cause2], and [cause3].
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The most common cause of [disease name] is [cause 1]. Less common causes of [disease name] include [cause 2], [cause 3], and [cause 4].
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The cause of [disease name] has not been identified. To review risk factors for the development of [disease name], click here.
Differentiating COVID-19-associated anosmia from other Diseases
[Disease name] must be differentiated from other diseases that cause [clinical feature 1], [clinical feature 2], and [clinical feature 3], such as [differential dx1], [differential dx2], and [differential dx3].
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[Disease name] must be differentiated from [[differential dx1], [differential dx2], and [differential dx3].
Epidemiology and Demographics
- Postviral anosmia constitutes 40% of all anosmia causes in adults.[1][6]
- Further studies are requiered to establish the incidence of anosmia in COVID-19+ patients.[1]
- Severe olfactory loss (complete anosmia) is estimated to have an estimated prevalence of around 5% in general population studies (independently of infection).[1][7]
The incidence/prevalence of [disease name] is approximately [number range] per 100,000 individuals worldwide.
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In [year], the incidence/prevalence of [disease name] was estimated to be [number range] cases per 100,000 individuals worldwide.
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In [year], the incidence of [disease name] is approximately [number range] per 100,000 individuals with a case-fatality rate of [number range]%.
Patients of all age groups may develop [disease name].
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The incidence of [disease name] increases with age; the median age at diagnosis is [#] years.
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[Disease name] commonly affects individuals younger than/older than [number of years] years of age.
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[Chronic disease name] is usually first diagnosed among [age group].
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[Acute disease name] commonly affects [age group].
There is no racial predilection to [disease name].
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[Disease name] usually affects individuals of the [race 1] race. [Race 2] individuals are less likely to develop [disease name].
[Disease name] affects men and women equally.
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[Gender 1] are more commonly affected by [disease name] than [gender 2]. The [gender 1] to [gender 2] ratio is approximately [number > 1] to 1.
The majority of [disease name] cases are reported in [geographical region].
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[Disease name] is a common/rare disease that tends to affect [patient population 1] and [patient population 2].
Risk Factors
Advanced age and male gender are risk factors for developing anosmia in patients with COVID-19 infection.[1][8][9]
There are no established risk factors for [disease name].
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The most potent risk factor in the development of [disease name] is [risk factor 1]. Other risk factors include [risk factor 2], [risk factor 3], and [risk factor 4].
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Common risk factors in the development of [disease name] include [risk factor 1], [risk factor 2], [risk factor 3], and [risk factor 4].
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Common risk factors in the development of [disease name] may be occupational, environmental, genetic, and viral.
Screening
- Several ENT societies in the United Kingdom and the United States, have advised to treat anosmia marker of SARS-CoV-2 infection.[10][11][12]
- The American Academy of Otolaryngology (AAO) proposed for anosmia, hyposmia, and dysgeusia to be added to the list of screening tools for COVID-19 in otherwise asymptomatic individuals.[12][10]
There is insufficient evidence to recommend routine screening for [disease/malignancy].
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According to the [guideline name], screening for [disease name] is not recommended.
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According to the [guideline name], screening for [disease name] by [test 1] is recommended every [duration] among patients with [condition 1], [condition 2], and [condition 3].
Natural History, Complications, and Prognosis
If left untreated, [#]% of patients with [disease name] may progress to develop [manifestation 1], [manifestation 2], and [manifestation 3].
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Common complications of [disease name] include [complication 1], [complication 2], and [complication 3].
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Prognosis is generally excellent/good/poor, and the 1/5/10-year mortality/survival rate of patients with [disease name] is approximately [#]%.
Diagnosis
Diagnostic Study of Choice
The diagnosis of [disease name] is made when at least [number] of the following [number] diagnostic criteria are met: [criterion 1], [criterion 2], [criterion 3], and [criterion 4].
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The diagnosis of [disease name] is based on the [criteria name] criteria, which include [criterion 1], [criterion 2], and [criterion 3].
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The diagnosis of [disease name] is based on the [definition name] definition, which includes [criterion 1], [criterion 2], and [criterion 3].
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There are no established criteria for the diagnosis of [disease name].
History and Symptoms
The majority of patients with [disease name] are asymptomatic.
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The hallmark of [disease name] is [finding]. A positive history of [finding 1] and [finding 2] is suggestive of [disease name]. The most common symptoms of [disease name] include [symptom 1], [symptom 2], and [symptom 3]. Common symptoms of [disease] include [symptom 1], [symptom 2], and [symptom 3]. Less common symptoms of [disease name] include [symptom 1], [symptom 2], and [symptom 3].
Physical Examination
Patients with [disease name] usually appear [general appearance]. Physical examination of patients with [disease name] is usually remarkable for [finding 1], [finding 2], and [finding 3].
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Common physical examination findings of [disease name] include [finding 1], [finding 2], and [finding 3].
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The presence of [finding(s)] on physical examination is diagnostic of [disease name].
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The presence of [finding(s)] on physical examination is highly suggestive of [disease name].
Laboratory Findings
An elevated/reduced concentration of serum/blood/urinary/CSF/other [lab test] is diagnostic of [disease name].
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Laboratory findings consistent with the diagnosis of [disease name] include [abnormal test 1], [abnormal test 2], and [abnormal test 3].
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[Test] is usually normal among patients with [disease name].
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Some patients with [disease name] may have elevated/reduced concentration of [test], which is usually suggestive of [progression/complication].
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There are no diagnostic laboratory findings associated with [disease name].
Electrocardiogram
There are no ECG findings associated with [disease name].
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An ECG may be helpful in the diagnosis of [disease name]. Findings on an ECG suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
X-ray
There are no x-ray findings associated with [disease name].
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An x-ray may be helpful in the diagnosis of [disease name]. Findings on an x-ray suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
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There are no x-ray findings associated with [disease name]. However, an x-ray may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].
Echocardiography or Ultrasound
There are no echocardiography/ultrasound findings associated with [disease name].
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Echocardiography/ultrasound may be helpful in the diagnosis of [disease name]. Findings on an echocardiography/ultrasound suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
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There are no echocardiography/ultrasound findings associated with [disease name]. However, an echocardiography/ultrasound may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].
CT scan
There are no CT scan findings associated with [disease name].
OR
[Location] CT scan may be helpful in the diagnosis of [disease name]. Findings on CT scan suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
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There are no CT scan findings associated with [disease name]. However, a CT scan may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].
MRI
There are no MRI findings associated with [disease name].
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[Location] MRI may be helpful in the diagnosis of [disease name]. Findings on MRI suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
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There are no MRI findings associated with [disease name]. However, a MRI may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].
Other Imaging Findings
There are no other imaging findings associated with [disease name].
OR
[Imaging modality] may be helpful in the diagnosis of [disease name]. Findings on an [imaging modality] suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
Other Diagnostic Studies
There are no other diagnostic studies associated with [disease name].
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[Diagnostic study] may be helpful in the diagnosis of [disease name]. Findings suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
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Other diagnostic studies for [disease name] include [diagnostic study 1], which demonstrates [finding 1], [finding 2], and [finding 3], and [diagnostic study 2], which demonstrates [finding 1], [finding 2], and [finding 3].
Treatment
Medical Therapy
There is no treatment for [disease name]; the mainstay of therapy is supportive care.
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Supportive therapy for [disease name] includes [therapy 1], [therapy 2], and [therapy 3].
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The majority of cases of [disease name] are self-limited and require only supportive care.
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[Disease name] is a medical emergency and requires prompt treatment.
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The mainstay of treatment for [disease name] is [therapy].
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The optimal therapy for [malignancy name] depends on the stage at diagnosis.
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[Therapy] is recommended among all patients who develop [disease name].
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Pharmacologic medical therapy is recommended among patients with [disease subclass 1], [disease subclass 2], and [disease subclass 3].
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Pharmacologic medical therapies for [disease name] include (either) [therapy 1], [therapy 2], and/or [therapy 3].
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Empiric therapy for [disease name] depends on [disease factor 1] and [disease factor 2].
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Patients with [disease subclass 1] are treated with [therapy 1], whereas patients with [disease subclass 2] are treated with [therapy 2].
Surgery
Surgical intervention is not recommended for the management of [disease name].
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Surgery is not the first-line treatment option for patients with [disease name]. Surgery is usually reserved for patients with either [indication 1], [indication 2], and [indication 3]
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The mainstay of treatment for [disease name] is medical therapy. Surgery is usually reserved for patients with either [indication 1], [indication 2], and/or [indication 3].
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The feasibility of surgery depends on the stage of [malignancy] at diagnosis.
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Surgery is the mainstay of treatment for [disease or malignancy].
Primary Prevention
There are no established measures for the primary prevention of [disease name].
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There are no available vaccines against [disease name].
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Effective measures for the primary prevention of [disease name] include [measure1], [measure2], and [measure3].
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[Vaccine name] vaccine is recommended for [patient population] to prevent [disease name]. Other primary prevention strategies include [strategy 1], [strategy 2], and [strategy 3].
Secondary Prevention
There are no established measures for the secondary prevention of [disease name].
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Effective measures for the secondary prevention of [disease name] include [strategy 1], [strategy 2], and [strategy 3].
References
- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 Hopkins C, Surda P, Kumar N (June 2020). "Presentation of new onset anosmia during the COVID-19 pandemic". Rhinology. 58 (3): 295–298. doi:10.4193/Rhin20.116. PMID 32277751 Check
|pmid=value (help). - ↑ Eccles R (November 2005). "Understanding the symptoms of the common cold and influenza". Lancet Infect Dis. 5 (11): 718–25. doi:10.1016/S1473-3099(05)70270-X. PMC 7185637 Check
|pmc=value (help). PMID 16253889. - ↑ 3.0 3.1 3.2 Dubé M, Le Coupanec A, Wong A, Rini JM, Desforges M, Talbot PJ (September 2018). "Axonal Transport Enables Neuron-to-Neuron Propagation of Human Coronavirus OC43". J. Virol. 92 (17). doi:10.1128/JVI.00404-18. PMC 6096804. PMID 29925652. Vancouver style error: initials (help)
- ↑ "Neue Corona-Symptome entdeckt: Virologe Hendrik Streeck zum Virus".
- ↑ "[단독]대구 확진자 3191명 중 15%, 후각이나 미각 잃었다 - 중앙일보".
- ↑ Zhu N, Zhang D, Wang W et al. A Novel Welge -Lussen A, Wolfensberger M. (2006). "Olfactory disorders following upper respiratory tract infections". Adv Otorhinolaryngol.
- ↑ Brämerson A, Johansson L, Ek L, Nordin S, Bende M (April 2004). "Prevalence of olfactory dysfunction: the skövde population-based study". Laryngoscope. 114 (4): 733–7. doi:10.1097/00005537-200404000-00026. PMID 15064632.
- ↑ Stogbauer J, Wirkner K, Engel C, Moebus S, Pundt N, Teismann H, Loffler M, Hummel T, Beule AG, Berger K (April 2020). "Prevalence and risk factors of smell dysfunction - a comparison between five German population-based studies". Rhinology. 58 (2): 184–191. doi:10.4193/Rhin19.181. PMID 31693018.
- ↑ Wang X, Zhang C, Xia X, Yang Y, Zhou C (October 2019). "Effect of gender on odor identification at different life stages: a meta-analysis". Rhinology. 57 (5): 322–330. doi:10.4193/Rhin19.005. PMID 31152646.
- ↑ 10.0 10.1 Robert Pellegrin, Keiland W. Cooper, Antonella Di Pizio, Paule V. Joseph, Surabhi Bhutani, Valentina Parma (2020). "Corona Viruses and the Chemical Senses:
Past, Present, and Future". Oxford University. line feed character in
|title=at position 40 (help) - ↑ "www.entuk.org" (PDF).
- ↑ 12.0 12.1 "AAO-HNSF 2020 Annual Meeting & OTO Experience | American Academy of Otolaryngology-Head and Neck Surgery".