COVID-19-associated anosmia: Difference between revisions

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==Historical Perspective==
==Historical Perspective==
[[COVID-19]] ([[SARS-CoV-2]]) [[outbreak]] initiated in December, 2019 in Wuhan, Hubei Province, China.<ref name="pmid32563019">{{cite journal |vauthors=Meng X, Deng Y, Dai Z, Meng Z |title=COVID-19 and anosmia: A review based on up-to-date knowledge |journal=Am J Otolaryngol |volume=41 |issue=5 |pages=102581 |date=June 2020 |pmid=32563019 |pmc=7265845 |doi=10.1016/j.amjoto.2020.102581 |url=}}</ref>  
 
* [[COVID-19]] ([[SARS-CoV-2]]) [[outbreak]] initiated in December, 2019 in Wuhan, Hubei Province, China.<ref name="pmid32563019">{{cite journal |vauthors=Meng X, Deng Y, Dai Z, Meng Z |title=COVID-19 and anosmia: A review based on up-to-date knowledge |journal=Am J Otolaryngol |volume=41 |issue=5 |pages=102581 |date=June 2020 |pmid=32563019 |pmc=7265845 |doi=10.1016/j.amjoto.2020.102581 |url=}}</ref>  


==Classification==
==Classification==
There is no established system for the classification of [[COVID-19]] associated [[anosmia]].
 
* There is no established system for the classification of [[COVID-19]] associated [[anosmia]].


==Pathophysiology==
==Pathophysiology==


* Now in day, more than 200 types of [[viruses]] are identified to cause [[anosmia]]; [[coronavirus]] [[Strain (biology)|strains]] (7 of them) are responsable of 10-15% of the cases.<ref name="pmid32277751" /><ref name="pmid16253889">{{cite journal |vauthors=Eccles R |title=Understanding the symptoms of the common cold and influenza |journal=Lancet Infect Dis |volume=5 |issue=11 |pages=718–25 |date=November 2005 |pmid=16253889 |pmc=7185637 |doi=10.1016/S1473-3099(05)70270-X |url=}}</ref><ref name="pmid32563019" />
*The extent of potential [[olfactory]] [[dysfunction]] due to [[COVID-19]] is still unclear.<ref name="pmid32563019" /><ref name="pmid29528615">{{cite journal |vauthors=Hummel T, Whitcroft KL, Andrews P, Altundag A, Cinghi C, Costanzo RM, Damm M, Frasnelli J, Gudziol H, Gupta N, Haehne A, Holbrook E, Hong SC, Hornung D, Hüttenbrink KB, Kamel R, Kobayashi M, Konstantinidis I, Landis BN, Leopold DA, Macchi A, Miwa T, Moesges R, Mullol J, Mueller CA, Ottaviano G, Passali GC, Philpott C, Pinto JM, Ramakrishnan VJ, Rombaux P, Roth Y, Schlosser RA, Shu B, Soler G, Stjärne P, Stuck BA, Vodicka J, Welge-Luessen A |title=Position paper on olfactory dysfunction |journal=Rhinol. Suppl. |volume=54 |issue=26 |pages=1–30 |date=March 2017 |pmid=29528615 |doi=10.4193/Rhino16.248 |url=}}</ref><nowiki/>
*The extent of potential [[olfactory]] [[dysfunction]] due to [[COVID-19]] is still unclear.<ref name="pmid32563019" /><ref name="pmid29528615">{{cite journal |vauthors=Hummel T, Whitcroft KL, Andrews P, Altundag A, Cinghi C, Costanzo RM, Damm M, Frasnelli J, Gudziol H, Gupta N, Haehne A, Holbrook E, Hong SC, Hornung D, Hüttenbrink KB, Kamel R, Kobayashi M, Konstantinidis I, Landis BN, Leopold DA, Macchi A, Miwa T, Moesges R, Mullol J, Mueller CA, Ottaviano G, Passali GC, Philpott C, Pinto JM, Ramakrishnan VJ, Rombaux P, Roth Y, Schlosser RA, Shu B, Soler G, Stjärne P, Stuck BA, Vodicka J, Welge-Luessen A |title=Position paper on olfactory dysfunction |journal=Rhinol. Suppl. |volume=54 |issue=26 |pages=1–30 |date=March 2017 |pmid=29528615 |doi=10.4193/Rhino16.248 |url=}}</ref>
*The [[genome]] sequence of (COVID-19) <nowiki/>[[SARS-CoV-2]] is a 29,903 bp single-stranded [[RNA]].<ref name="pmid32563019" /><ref name="pmid32167747">{{cite journal |vauthors=Baig AM, Khaleeq A, Ali U, Syeda H |title=Evidence of the COVID-19 Virus Targeting the CNS: Tissue Distribution, Host-Virus Interaction, and Proposed Neurotropic Mechanisms |journal=ACS Chem Neurosci |volume=11 |issue=7 |pages=995–998 |date=April 2020 |pmid=32167747 |pmc=7094171 |doi=10.1021/acschemneuro.0c00122 |url=}}</ref>
* Human [[Strain (biology)|strains]] of [[Coronavirus, SARS associated|coronavirus]] ([[Novel human coronavirus infection|HCoV]]<nowiki/>s) can infect and spread through the [[olfactory bulb]].<ref name="pmid29925652">{{cite journal |vauthors=Dubé M, Le Coupanec A, Wong AHM, Rini JM, Desforges M, Talbot PJ |title=Axonal Transport Enables Neuron-to-Neuron Propagation of Human Coronavirus OC43 |journal=J. Virol. |volume=92 |issue=17 |pages= |date=September 2018 |pmid=29925652 |pmc=6096804 |doi=10.1128/JVI.00404-18 |url=}}</ref><ref name="pmid32277751" />
*[[Pathogenicity]], [[virology]], and predi<nowiki/>lection for [[infection]] site are different for every [[virus]]. The main pathogenic site for [[COVID-19]] is [[throat]] and [[nose]].<ref name="pmid32303590">{{cite journal |vauthors=Rockx B, Kuiken T, Herfst S, Bestebroer T, Lamers MM, Oude Munnink BB, de Meulder D, van Amerongen G, van den Brand J, Okba NMA, Schipper D, van Run P, Leijten L, Sikkema R, Verschoor E, Verstrepen B, Bogers W, Langermans J, Drosten C, Fentener van Vlissingen M, Fouchier R, de Swart R, Koopmans M, Haagmans BL |title=Comparative pathogenesis of COVID-19, MERS, and SARS in a nonhuman primate model |journal=Science |volume=368 |issue=6494 |pages=1012–1015 |date=May 2020 |pmid=32303590 |pmc=7164679 |doi=10.1126/science.abb7314 |url=}}</ref><ref name="pmid32563019" />
*The [[genome]] sequence of [[SARS-CoV-2]] <nowiki/>is a 29,903 bp single-stranded [[RNA]].<ref name="pmid32563019" /><ref name="pmid32167747">{{cite journal |vauthors=Baig AM, Khaleeq A, Ali U, Syeda H |title=Evidence of the COVID-19 Virus Targeting the CNS: Tissue Distribution, Host-Virus Interaction, and Proposed Neurotropic Mechanisms |journal=ACS Chem Neurosci |volume=11 |issue=7 |pages=995–998 |date=April 2020 |pmid=32167747 |pmc=7094171 |doi=10.1021/acschemneuro.0c00122 |url=}}</ref>
*[[Viral load|Viral loads]] of COVID-19 are higher<nowiki/> in the [[nasal cavity]] than any other site of [[infection]] ([[throat]], [[lungs]]), both, in [[symptomatic]] and [[asymptomatic]] individuals.<ref name="pmid32074444">{{cite journal |vauthors=Zou L, Ruan F, Huang M, Liang L, Huang H, Hong Z, Yu J, Kang M, Song Y, Xia J, Guo Q, Song T, He J, Yen HL, Peiris M, Wu J |title=SARS-CoV-2 Viral Load in Upper Respiratory Specimens of Infected Patients |journal=N. Engl. J. Med. |volume=382 |issue=12 |pages=1177–1179 |date=March 2020 |pmid=32074444 |pmc=7121626 |doi=10.1056/NEJMc2001737 |url=}}</ref><ref name="pmid32563019" />
* The mechanism of [[Central nervous system|central nervous system (CNS)]] invasion is unclear.<ref name="pmid29925652" />
*<nowiki/>Studies suggest that [[viruses]] may propagate from the [[Nasal cavity|nasal cavit]]<nowiki/>y to the [[olfactory bulb]] through neuron-to-neuron [[axonal]] transport or passive diffusion of released viral particles.<ref name="pmid29925652" />
*Due to the special anatomy of the [[olfactory system]], [[COVID-19]] [[Virus (biology)|vi]]<nowiki/>[[Virus (biology)|rus]] may invade the [[Central nervous system infection|central nervous system infections]] via the [[cribriform plate]].<ref name="pmid32563019" /><ref name="pmid23601101">{{cite journal |vauthors=Koyuncu OO, Hogue IB, Enquist LW |title=Virus infections in the nervous system |journal=Cell Host Microbe |volume=13 |issue=4 |pages=379–93 |date=April 2013 |pmid=23601101 |pmc=3647473 |doi=10.1016/j.chom.2013.03.010 |url=}}</ref>
*A  study from Germany described that approximately two thirds o<nowiki/>f confirmed [[COVID-19]] infections presented [[anosmia]] and [[dysgeusia]] at some point of the [[disease]].<ref name="urlNeue Corona-Symptome entdeckt: Virologe Hendrik Streeck zum Virus">{{cite web |url=https://www.faz.net/aktuell/gesellschaft/gesundheit/coronavirus/neue-corona-symptome-entdeckt-virologe-hendrik-streeck-zum-virus-16681450.html |title=Neue Corona-Symptome entdeckt: Virologe Hendrik Streeck zum Virus |format= |work= |accessdate=}}</ref> Another study from South Korea, with 3191 mild-[[disease]] patients reported only 15.3% of [[anosmia]] or [[dysgeusia]].<ref name="url[단독]대구 확진자 3191명 중 15%, 후각이나 미각 잃었다 - 중앙일보">{{cite web |url=https://news.joins.com/article/23738003?cloc=joongang-mhomegroup6&fbclid=IwAR33__i-aKtLN2MzCs5A |title=[단독]대구 확진자 3191명 중 15%, 후각이나 미각 잃었다 - 중앙일보 |format= |work= |accessdate=}}</ref>
* In a study, 74.4% reported complete loss of [[smell]].<ref name="pmid32277751" />
*[[Anosmia]] may occur as the only symptom of [[COVID-19]] in approximately 16% of individuals.<ref name="pmid32277751" />
*[[Anosmia]] occurs more commonly after the onset of other [[symptoms]]. In a study involving 1325 participants with anosmia (with no confirmatory [[COVID-19 diagnostic study of choice|COVID-19 test]]), 13% reported [[anosmia]] before their onset, 38.4% at the same time, and in 48.6% after the onset of [[symptoms]].<ref name="pmid32277751" />
*[[Pathogenicity]], [[virology]], and predilection for [[infection]] site are different for every [[virus]]. The main pathogenic site for [[COVID-19]] is [[throat]] and [[nose]].<ref name="pmid32303590">{{cite journal |vauthors=Rockx B, Kuiken T, Herfst S, Bestebroer T, Lamers MM, Oude Munnink BB, de Meulder D, van Amerongen G, van den Brand J, Okba NMA, Schipper D, van Run P, Leijten L, Sikkema R, Verschoor E, Verstrepen B, Bogers W, Langermans J, Drosten C, Fentener van Vlissingen M, Fouchier R, de Swart R, Koopmans M, Haagmans BL |title=Comparative pathogenesis of COVID-19, MERS, and SARS in a nonhuman primate model |journal=Science |volume=368 |issue=6494 |pages=1012–1015 |date=May 2020 |pmid=32303590 |pmc=7164679 |doi=10.1126/science.abb7314 |url=}}</ref><ref name="pmid32563019" />
*[[Viral load|Viral loads]] of COVID-19 are higher in the [[nasal cavity]] than any other site of [[infection]] ([[throat]], [[lungs]]), both, in [[symptomatic]] and [[asymptomatic]] individuals.<ref name="pmid32074444">{{cite journal |vauthors=Zou L, Ruan F, Huang M, Liang L, Huang H, Hong Z, Yu J, Kang M, Song Y, Xia J, Guo Q, Song T, He J, Yen HL, Peiris M, Wu J |title=SARS-CoV-2 Viral Load in Upper Respiratory Specimens of Infected Patients |journal=N. Engl. J. Med. |volume=382 |issue=12 |pages=1177–1179 |date=March 2020 |pmid=32074444 |pmc=7121626 |doi=10.1056/NEJMc2001737 |url=}}</ref><ref name="pmid32563019" />
*It is thought that [[Goblet cell|Goblet cells]] and [[ciliated cells]] of the [[nasal mucosa]] may be the initial site of [[COVID-19]] infection when [[transmission]] is through airway.<ref name="pmid32563019" /><ref name="pmid32327758">{{cite journal |vauthors=Sungnak W, Huang N, Bécavin C, Berg M, Queen R, Litvinukova M, Talavera-López C, Maatz H, Reichart D, Sampaziotis F, Worlock KB, Yoshida M, Barnes JL |title=SARS-CoV-2 entry factors are highly expressed in nasal epithelial cells together with innate immune genes |journal=Nat. Med. |volume=26 |issue=5 |pages=681–687 |date=May 2020 |pmid=32327758 |doi=10.1038/s41591-020-0868-6 |url=}}</ref>


<br />
<br />
*
* The mechanism of [[Central nervous system|central nervous system (CNS)]] invasion is unclear.<ref name="pmid29925652">{{cite journal |vauthors=Dubé M, Le Coupanec A, Wong AHM, Rini JM, Desforges M, Talbot PJ |title=Axonal Transport Enables Neuron-to-Neuron Propagation of Human Coronavirus OC43 |journal=J. Virol. |volume=92 |issue=17 |pages= |date=September 2018 |pmid=29925652 |pmc=6096804 |doi=10.1128/JVI.00404-18 |url=}}</ref>
*Due to the special anatomy of the [[olfactory system]], [[COVID-19]] [[Virus (biology)|vi]][[Virus (biology)|rus]] may invade the [[Central nervous system infection|central nervous system infections]] via the [[cribriform plate]].<ref name="pmid32563019" /><ref name="pmid23601101">{{cite journal |vauthors=Koyuncu OO, Hogue IB, Enquist LW |title=Virus infections in the nervous system |journal=Cell Host Microbe |volume=13 |issue=4 |pages=379–93 |date=April 2013 |pmid=23601101 |pmc=3647473 |doi=10.1016/j.chom.2013.03.010 |url=}}</ref>
*It is thought that [[Goblet cell|Goblet cells]] and [[ciliated cells]] of the [[nasal mucosa]] may be the initial site of [[COVID-19]] infection when [[transmission]] is through airway.<ref name="pmid32563019" /><ref name="pmid32327758">{{cite journal |vauthors=Sungnak W, Huang N, Bécavin C, Berg M, Queen R, Litvinukova M, Talavera-López C, Maatz H, Reichart D, Sampaziotis F, Worlock KB, Yoshida M, Barnes JL |title=SARS-CoV-2 entry factors are highly expressed in nasal epithelial cells together with innate immune genes |journal=Nat. Med. |volume=26 |issue=5 |pages=681–687 |date=May 2020 |pmid=32327758 |doi=10.1038/s41591-020-0868-6 |url=}}</ref>
*<nowiki/><nowiki/><nowiki/><nowiki/><nowiki/>Studies suggest that [[viruses]] may propagate from the [[Nasal cavity|nasal cavit]]<nowiki/>y to the [[olfactory bulb]] through neuron-to-neuron [[axonal]] transport or passive diffusion of released viral particles.<ref name="pmid29925652" />


==Causes==
==Causes==
Disease name] may be caused by [cause1], [cause2], or [cause3].
Human [[Strain (biology)|strains]] of [[Coronavirus, SARS associated|coronavirus]] ([[Novel human coronavirus infection|HCoV]]<nowiki/>s) can infect and spread through the [[olfactory bulb]].<ref name="pmid29925652" /><ref name="pmid32277751" />
 
OR
 
Common causes of [disease] include [cause1], [cause2], and [cause3].
 
OR
 
The most common cause of [disease name] is [cause 1]. Less common causes of [disease name] include [cause 2], [cause 3], and [cause 4].
 
OR


The cause of [disease name] has not been identified. To review risk factors for the development of [disease name], click [[Pericarditis causes#Overview|here]].
Now in day, more than 200 types of [[viruses]] are identified to cause [[anosmia]]; [[coronavirus]] [[Strain (biology)|strains]] (7 of them) are responsable of 10-15% of the cases.<ref name="pmid32277751" /><ref name="pmid16253889">{{cite journal |vauthors=Eccles R |title=Understanding the symptoms of the common cold and influenza |journal=Lancet Infect Dis |volume=5 |issue=11 |pages=718–25 |date=November 2005 |pmid=16253889 |pmc=7185637 |doi=10.1016/S1473-3099(05)70270-X |url=}}</ref><ref name="pmid32563019" />


==Differentiating COVID-19-associated anosmia from other Diseases==
==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].
<br />
 
OR
 
[Disease name] must be differentiated from [[differential dx1], [differential dx2], and [differential dx3].


==Epidemiology and Demographics==
==Epidemiology and Demographics==


* Postviral [[anosmia]] constitutes 40% of all [[anosmia]] causes in adults.<ref name="pmid32277751">{{cite journal |vauthors=Hopkins C, Surda P, Kumar N |title=Presentation of new onset anosmia during the COVID-19 pandemic |journal=Rhinology |volume=58 |issue=3 |pages=295–298 |date=June 2020 |pmid=32277751 |doi=10.4193/Rhin20.116 |url=}}</ref><ref>{{Cite journal|last=Zhu N, Zhang D, Wang W et al. A Novel Welge -Lussen A, Wolfensberger M.|first=|date=2006|title=Olfactory disorders following upper respiratory tract infections|url=|journal=Adv Otorhinolaryngol|volume=|pages=|via=}}</ref>
* Postviral [[anosmia]] constitutes 40% of all [[anosmia]] causes in adults.<ref name="pmid32277751">{{cite journal |vauthors=Hopkins C, Surda P, Kumar N |title=Presentation of new onset anosmia during the COVID-19 pandemic |journal=Rhinology |volume=58 |issue=3 |pages=295–298 |date=June 2020 |pmid=32277751 |doi=10.4193/Rhin20.116 |url=}}</ref><ref>{{Cite journal|last=Zhu N, Zhang D, Wang W et al. A Novel Welge -Lussen A, Wolfensberger M.|first=|date=2006|title=Olfactory disorders following upper respiratory tract infections|url=|journal=Adv Otorhinolaryngol|volume=|pages=|via=}}</ref>
* Further studies are requiered to establish the incidence of [[anosmia]] in [[COVID-19]]+ patients.<ref name="pmid32277751" />
* Severe [[Olfaction|olfactory]] loss (complete [[anosmia]]) is estimated to have an estimated [[prevalence]] of around 5% in general population studies (independently of infection).<ref name="pmid32277751" /><ref name="pmid15064632">{{cite journal |vauthors=Brämerson A, Johansson L, Ek L, Nordin S, Bende M |title=Prevalence of olfactory dysfunction: the skövde population-based study |journal=Laryngoscope |volume=114 |issue=4 |pages=733–7 |date=April 2004 |pmid=15064632 |doi=10.1097/00005537-200404000-00026 |url=}}</ref>
* Severe [[Olfaction|olfactory]] loss (complete [[anosmia]]) is estimated to have an estimated [[prevalence]] of around 5% in general population studies (independently of infection).<ref name="pmid32277751" /><ref name="pmid15064632">{{cite journal |vauthors=Brämerson A, Johansson L, Ek L, Nordin S, Bende M |title=Prevalence of olfactory dysfunction: the skövde population-based study |journal=Laryngoscope |volume=114 |issue=4 |pages=733–7 |date=April 2004 |pmid=15064632 |doi=10.1097/00005537-200404000-00026 |url=}}</ref>
*Further studies are requiered to establish the incidence of [[anosmia]] in [[COVID-19]]+ patients.<ref name="pmid32277751" />
*The [[incidence]] of [[anosmia]] related to [[COVID-19]] vary widely from one study to the other:


The incidence/prevalence of [disease name] is approximately [number range] per 100,000 individuals worldwide.
** A  study from Germany described that approximately two thirds of confirmed [[COVID-19]] infections presented [[anosmia]] and [[dysgeusia]] at some point of the [[disease]].<ref name="urlNeue Corona-Symptome entdeckt: Virologe Hendrik Streeck zum Virus">{{cite web |url=https://www.faz.net/aktuell/gesellschaft/gesundheit/coronavirus/neue-corona-symptome-entdeckt-virologe-hendrik-streeck-zum-virus-16681450.html |title=Neue Corona-Symptome entdeckt: Virologe Hendrik Streeck zum Virus |format= |work= |accessdate=}}</ref>
** A study from South Korea, with 3191 mild-[[disease]] patients reported only 15.3% of [[anosmia]] or [[dysgeusia]].<ref name="url[단독]대구 확진자 3191명 중 15%, 후각이나 미각 잃었다 - 중앙일보">{{cite web |url=https://news.joins.com/article/23738003?cloc=joongang-mhomegroup6&fbclid=IwAR33__i-aKtLN2MzCs5A |title=[단독]대구 확진자 3191명 중 15%, 후각이나 미각 잃었다 - 중앙일보 |format= |work= |accessdate=}}</ref>
** In a [[Retrospective study|retrospective]] study made by Klopfenstein et al., 54 (47%) out of 114 confirmed [[COVID-19]] patients presented with [[anosmia]].<ref name="pmid32305563">{{cite journal |vauthors=Klopfenstein T, Kadiane-Oussou NJ, Toko L, Royer PY, Lepiller Q, Gendrin V, Zayet S |title=Features of anosmia in COVID-19 |journal=Med Mal Infect |volume= |issue= |pages= |date=April 2020 |pmid=32305563 |pmc=7162775 |doi=10.1016/j.medmal.2020.04.006 |url=}}</ref>
* The [[prevalence]] of  [[anosmia]] related to [[COVID-19]] has also varied from one country to another:


OR
<br />
 
In [year], the incidence/prevalence of [disease name] was estimated to be [number range] cases per 100,000 individuals worldwide.
 
OR
 
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].
 
OR
 
The incidence of [disease name] increases with age; the median age at diagnosis is [#] years.
 
OR
 
[Disease name] commonly affects individuals younger than/older than [number of years] years of age.
 
OR
 
[Chronic disease name] is usually first diagnosed among [age group].
 
OR
 
[Acute disease name] commonly affects [age group].
 
 
 
There is no racial predilection to [disease name].
 
OR
 
[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.
 
OR
 
[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].
 
OR
 
[Disease name] is a common/rare disease that tends to affect [patient population 1] and [patient population 2].


==Risk Factors==
==Risk Factors==
Advanced [[age]] and [[male]] gender are [[risk factors]] for developing [[anosmia]] in patients with [[COVID-19]] infection.<ref name="pmid32277751" /><ref name="pmid31693018">{{cite journal |vauthors=Stogbauer J, Wirkner K, Engel C, Moebus S, Pundt N, Teismann H, Loffler M, Hummel T, Beule AG, Berger K |title=Prevalence and risk factors of smell dysfunction - a comparison between five German population-based studies |journal=Rhinology |volume=58 |issue=2 |pages=184–191 |date=April 2020 |pmid=31693018 |doi=10.4193/Rhin19.181 |url=}}</ref><ref name="pmid31152646">{{cite journal |vauthors=Wang X, Zhang C, Xia X, Yang Y, Zhou C |title=Effect of gender on odor identification at different life stages: a meta-analysis |journal=Rhinology |volume=57 |issue=5 |pages=322–330 |date=October 2019 |pmid=31152646 |doi=10.4193/Rhin19.005 |url=}}</ref>


There are no established risk factors for [disease name].
* The most common identified [[risk factors]] for developing [[anosmia]] in patients with [[COVID-19]] infection are:<ref name="pmid32277751" /><ref name="pmid31693018">{{cite journal |vauthors=Stogbauer J, Wirkner K, Engel C, Moebus S, Pundt N, Teismann H, Loffler M, Hummel T, Beule AG, Berger K |title=Prevalence and risk factors of smell dysfunction - a comparison between five German population-based studies |journal=Rhinology |volume=58 |issue=2 |pages=184–191 |date=April 2020 |pmid=31693018 |doi=10.4193/Rhin19.181 |url=}}</ref><ref name="pmid31152646">{{cite journal |vauthors=Wang X, Zhang C, Xia X, Yang Y, Zhou C |title=Effect of gender on odor identification at different life stages: a meta-analysis |journal=Rhinology |volume=57 |issue=5 |pages=322–330 |date=October 2019 |pmid=31152646 |doi=10.4193/Rhin19.005 |url=}}</ref>
 
** Advanced [[age]]<ref name="pmid31693018" />
OR
** [[Male]] gender<ref name="pmid31152646" />
 
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].
 
OR
 
Common risk factors in the development of [disease name] include [risk factor 1], [risk factor 2], [risk factor 3], and [risk factor 4].
 
OR
 
Common risk factors in the development of [disease name] may be occupational, environmental, genetic, and viral.


==Screening==
==Screening==
Line 142: Line 68:
* 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.<ref name="urlAAO-HNSF 2020 Annual Meeting & OTO Experience | American Academy of Otolaryngology-Head and Neck Surgery" /><ref name=":0" />
* 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.<ref name="urlAAO-HNSF 2020 Annual Meeting & OTO Experience | American Academy of Otolaryngology-Head and Neck Surgery" /><ref name=":0" />


There is insufficient evidence to recommend routine screening for [disease/malignancy].
<br />
 
OR
 
According to the [guideline name], screening for [disease name] is not recommended.
 
OR
 
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==
==Natural History, Complications, and Prognosis==
If left untreated, [#]% of patients with [disease name] may progress to develop [manifestation 1], [manifestation 2], and [manifestation 3].
[[Anosmia]] related to [[COVID-19]], typically has a duration of 8.96 days.<ref name="pmid32563019" /><ref name="pmid323055632" />
 
OR
 
Common complications of [disease name] include [complication 1], [complication 2], and [complication 3].
 
OR


Prognosis is generally excellent/good/poor, and the 1/5/10-year mortality/survival rate of patients with [disease name] is approximately [#]%.
Approximately 98% of patients with [[anosmia]] related to [[COVID-19]] recover within 28 days.<ref name="pmid32563019" /><ref name="pmid323055632" />


==Diagnosis==
==Diagnosis==
===Diagnostic Study of Choice===
===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].
<br />
 
OR
 
The diagnosis of [disease name] is based on the [criteria name] criteria, which include [criterion 1], [criterion 2], and [criterion 3].
 
OR
 
The diagnosis of [disease name] is based on the [definition name] definition, which includes [criterion 1], [criterion 2], and [criterion 3].
 
OR
 
There are no established criteria for the diagnosis of [disease name].


===History and Symptoms===
===History and Symptoms===
The majority of patients with [disease name] are asymptomatic.


OR
* [[Anosmia]] may occur suddenly as the only symptom of [[COVID-19]] in approximately 16% of individuals.<ref name="pmid32277751" /><ref name="pmid32319971">{{cite journal |vauthors=Heidari F, Karimi E, Firouzifar M, Khamushian P, Ansari R, Mohammadi Ardehali M, Heidari F |title=Anosmia as a prominent symptom of COVID-19 infection |journal=Rhinology |volume=58 |issue=3 |pages=302–303 |date=June 2020 |pmid=32319971 |doi=10.4193/Rhin20.140 |url=}}</ref>
 
* In a study, 74.4% reported complete loss of [[smell]].<ref name="pmid32277751" />
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].
* [[Anosmia]] occurs more commonly after the onset of other [[symptoms]]. In a study involving 1325 participants with anosmia (with no confirmatory [[COVID-19 diagnostic study of choice|COVID-19 test]]), 13% reported [[anosmia]] before their onset, 38.4% at the same time, and in 48.6% after the onset of [[symptoms]].<ref name="pmid32277751" />
* A study reports that [[anosmia]] typically developes after 4.4 days of [[COVID-19]] [[infection]].<ref name="pmid323055632">{{cite journal |vauthors=Klopfenstein T, Kadiane-Oussou NJ, Toko L, Royer PY, Lepiller Q, Gendrin V, Zayet S |title=Features of anosmia in COVID-19 |journal=Med Mal Infect |volume= |issue= |pages= |date=April 2020 |pmid=32305563 |pmc=7162775 |doi=10.1016/j.medmal.2020.04.006 |url=}}</ref><ref name="pmid32563019" />


===Physical Examination===
===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].
<br />
 
OR
 
Common physical examination findings of [disease name] include [finding 1], [finding 2], and [finding 3].
 
OR
 
The presence of [finding(s)] on physical examination is diagnostic of [disease name].
 
OR
 
The presence of [finding(s)] on physical examination is highly suggestive of [disease name].


===Laboratory Findings===
===Laboratory Findings===
An elevated/reduced concentration of serum/blood/urinary/CSF/other [lab test] is diagnostic of [disease name].
<br />
 
OR
 
Laboratory findings consistent with the diagnosis of [disease name] include [abnormal test 1], [abnormal test 2], and [abnormal test 3].
 
OR
 
[Test] is usually normal among patients with [disease name].
 
OR
 
Some patients with [disease name] may have elevated/reduced concentration of [test], which is usually suggestive of [progression/complication].
 
OR
 
There are no diagnostic laboratory findings associated with [disease name].


===Electrocardiogram===
===Electrocardiogram===
There are no ECG findings associated with [disease name].
<br />
 
OR
 
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===
===X-ray===
There are no x-ray findings associated with [disease name].
<br />
 
OR
 
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].
 
OR
 
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===
===Echocardiography or Ultrasound===
There are no echocardiography/ultrasound  findings associated with [disease name].
<br />
 
OR
 
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].
 
OR
 
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===
===CT scan===
There are no CT scan findings associated with [disease name].
<br />
 
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].
 
OR
 
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===
===MRI===
There are no MRI findings associated with [disease name].
<br />
 
OR
 
[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].
 
OR
 
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===
===Other Imaging Findings===
There are no other imaging findings associated with [disease name].
<br />
 
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===
===Other Diagnostic Studies===
There are no other diagnostic studies associated with [disease name].
<br />
 
OR
 
[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].
 
OR
 
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==
==Treatment==
===Medical Therapy===
===Medical Therapy===
There is no treatment for [disease name]; the mainstay of therapy is supportive care.
<br />
 
OR
 
Supportive therapy for [disease name] includes [therapy 1], [therapy 2], and [therapy 3].
 
OR
 
The majority of cases of [disease name] are self-limited and require only supportive care.
 
OR
 
[Disease name] is a medical emergency and requires prompt treatment.
 
OR
 
The mainstay of treatment for [disease name] is [therapy].
 
OR
The optimal therapy for [malignancy name] depends on the stage at diagnosis.
 
OR
 
[Therapy] is recommended among all patients who develop [disease name].
 
OR
 
Pharmacologic medical therapy is recommended among patients with [disease subclass 1], [disease subclass 2], and [disease subclass 3].
 
OR
 
Pharmacologic medical therapies for [disease name] include (either) [therapy 1], [therapy 2], and/or [therapy 3].
 
OR
 
Empiric therapy for [disease name] depends on [disease factor 1] and [disease factor 2].
 
OR
 
Patients with [disease subclass 1] are treated with [therapy 1], whereas patients with [disease subclass 2] are treated with [therapy 2].


===Surgery===
===Surgery===
Surgical intervention is not recommended for the management of [disease name].
<br />
 
OR
 
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]
 
OR
 
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].
 
OR
 
The feasibility of surgery depends on the stage of [malignancy] at diagnosis.
 
OR
 
Surgery is the mainstay of treatment for [disease or malignancy].


===Primary Prevention===
===Primary Prevention===
There are no established measures for the primary prevention of [disease name].
<br />
 
OR
 
There are no available vaccines against [disease name].
 
OR
 
Effective measures for the primary prevention of [disease name] include [measure1], [measure2], and [measure3].
 
OR
 
[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===
===Secondary Prevention===
There are no established measures for the secondary prevention of [disease name].
<br />
 
OR
 
Effective measures for the secondary prevention of [disease name] include [strategy 1], [strategy 2], and [strategy 3].


==References==
==References==

Revision as of 14:11, 3 July 2020

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Experimental / Informatics

List of terms related to 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 symptom of COVID-19 infection, and may be the most common sign of infection due to this virus.[1]

The extent of potential olfactory dysfunction due to COVID-19 is still unclear.[2]

Historical Perspective

Classification

  • There is no established system for the classification of COVID-19 associated anosmia.

Pathophysiology


Causes

Human strains of coronavirus (HCoVs) can infect and spread through the olfactory bulb.[7][1]

Now in day, more than 200 types of viruses are identified to cause anosmia; coronavirus strains (7 of them) are responsable of 10-15% of the cases.[1][10][2]

Differentiating COVID-19-associated anosmia from other Diseases


Epidemiology and Demographics


Risk Factors

Screening


Natural History, Complications, and Prognosis

Anosmia related to COVID-19, typically has a duration of 8.96 days.[2][21]

Approximately 98% of patients with anosmia related to COVID-19 recover within 28 days.[2][21]

Diagnosis

Diagnostic Study of Choice


History and Symptoms

Physical Examination


Laboratory Findings


Electrocardiogram


X-ray


Echocardiography or Ultrasound


CT scan


MRI


Other Imaging Findings


Other Diagnostic Studies


Treatment

Medical Therapy


Surgery


Primary Prevention


Secondary Prevention


References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 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).
  2. 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 Meng X, Deng Y, Dai Z, Meng Z (June 2020). "COVID-19 and anosmia: A review based on up-to-date knowledge". Am J Otolaryngol. 41 (5): 102581. doi:10.1016/j.amjoto.2020.102581. PMC 7265845 Check |pmc= value (help). PMID 32563019 Check |pmid= value (help).
  3. Hummel T, Whitcroft KL, Andrews P, Altundag A, Cinghi C, Costanzo RM, Damm M, Frasnelli J, Gudziol H, Gupta N, Haehne A, Holbrook E, Hong SC, Hornung D, Hüttenbrink KB, Kamel R, Kobayashi M, Konstantinidis I, Landis BN, Leopold DA, Macchi A, Miwa T, Moesges R, Mullol J, Mueller CA, Ottaviano G, Passali GC, Philpott C, Pinto JM, Ramakrishnan VJ, Rombaux P, Roth Y, Schlosser RA, Shu B, Soler G, Stjärne P, Stuck BA, Vodicka J, Welge-Luessen A (March 2017). "Position paper on olfactory dysfunction". Rhinol. Suppl. 54 (26): 1–30. doi:10.4193/Rhino16.248. PMID 29528615.
  4. Baig AM, Khaleeq A, Ali U, Syeda H (April 2020). "Evidence of the COVID-19 Virus Targeting the CNS: Tissue Distribution, Host-Virus Interaction, and Proposed Neurotropic Mechanisms". ACS Chem Neurosci. 11 (7): 995–998. doi:10.1021/acschemneuro.0c00122. PMC 7094171 Check |pmc= value (help). PMID 32167747 Check |pmid= value (help).
  5. Rockx B, Kuiken T, Herfst S, Bestebroer T, Lamers MM, Oude Munnink BB, de Meulder D, van Amerongen G, van den Brand J, Okba N, Schipper D, van Run P, Leijten L, Sikkema R, Verschoor E, Verstrepen B, Bogers W, Langermans J, Drosten C, Fentener van Vlissingen M, Fouchier R, de Swart R, Koopmans M, Haagmans BL (May 2020). "Comparative pathogenesis of COVID-19, MERS, and SARS in a nonhuman primate model". Science. 368 (6494): 1012–1015. doi:10.1126/science.abb7314. PMC 7164679 Check |pmc= value (help). PMID 32303590 Check |pmid= value (help). Vancouver style error: initials (help)
  6. Zou L, Ruan F, Huang M, Liang L, Huang H, Hong Z, Yu J, Kang M, Song Y, Xia J, Guo Q, Song T, He J, Yen HL, Peiris M, Wu J (March 2020). "SARS-CoV-2 Viral Load in Upper Respiratory Specimens of Infected Patients". N. Engl. J. Med. 382 (12): 1177–1179. doi:10.1056/NEJMc2001737. PMC 7121626 Check |pmc= value (help). PMID 32074444 Check |pmid= value (help).
  7. 7.0 7.1 7.2 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)
  8. Koyuncu OO, Hogue IB, Enquist LW (April 2013). "Virus infections in the nervous system". Cell Host Microbe. 13 (4): 379–93. doi:10.1016/j.chom.2013.03.010. PMC 3647473. PMID 23601101.
  9. Sungnak W, Huang N, Bécavin C, Berg M, Queen R, Litvinukova M, Talavera-López C, Maatz H, Reichart D, Sampaziotis F, Worlock KB, Yoshida M, Barnes JL (May 2020). "SARS-CoV-2 entry factors are highly expressed in nasal epithelial cells together with innate immune genes". Nat. Med. 26 (5): 681–687. doi:10.1038/s41591-020-0868-6. PMID 32327758 Check |pmid= value (help).
  10. 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.
  11. 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.
  12. 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.
  13. "Neue Corona-Symptome entdeckt: Virologe Hendrik Streeck zum Virus".
  14. "[단독]대구 확진자 3191명 중 15%, 후각이나 미각 잃었다 - 중앙일보".
  15. Klopfenstein T, Kadiane-Oussou NJ, Toko L, Royer PY, Lepiller Q, Gendrin V, Zayet S (April 2020). "Features of anosmia in COVID-19". Med Mal Infect. doi:10.1016/j.medmal.2020.04.006. PMC 7162775 Check |pmc= value (help). PMID 32305563 Check |pmid= value (help).
  16. 16.0 16.1 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.
  17. 17.0 17.1 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.
  18. 18.0 18.1 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)
  19. "www.entuk.org" (PDF).
  20. 20.0 20.1 "AAO-HNSF 2020 Annual Meeting & OTO Experience | American Academy of Otolaryngology-Head and Neck Surgery".
  21. 21.0 21.1 21.2 Klopfenstein T, Kadiane-Oussou NJ, Toko L, Royer PY, Lepiller Q, Gendrin V, Zayet S (April 2020). "Features of anosmia in COVID-19". Med Mal Infect. doi:10.1016/j.medmal.2020.04.006. PMC 7162775 Check |pmc= value (help). PMID 32305563 Check |pmid= value (help).
  22. Heidari F, Karimi E, Firouzifar M, Khamushian P, Ansari R, Mohammadi Ardehali M, Heidari F (June 2020). "Anosmia as a prominent symptom of COVID-19 infection". Rhinology. 58 (3): 302–303. doi:10.4193/Rhin20.140. PMID 32319971 Check |pmid= value (help).


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