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ANOSMIA AND COVID: A RELATIONSHIP STILL NOT CLARIFIED
Thayz Regina Portes Abrahão1
Bruna Aparecida Krichak2
Raquel Pires Bispo Andrade3
Thaina de Souza Gomes4
Shirley Gabriely da Silva Guedes5
Luma Caroline Godoy6
Isabelle Begalli Vicentin7
Gabriela de Sousa Marques8
Katiele Martins Duarte9
Ana Michelli Luis Gimenez10
Abstract: For a future doctor it is essential to know the pathophysiology of the diseases that aect
their patients, so that they perform ecient care and if they do not nd the cure leave the least possible
damage with the best quality of life. Although anosmia is a mild symptom among patients aected by
Covid 19, it brings consequences on the quality of life of the individual. Even being a pathology to be
claried in several points and despite being a symptom leads, it can lead to patient compromise in other
areas, such as psychological. We must bear in mind that every human being is a bio-psycho-social
being and although SARS-Cov-2 is a biological form it brings psychological damage to those infected.
1 Academic of the Medicine Course at the Central University of Paraguay
2 Academic of the Medicine Course at the Central University of Paraguay
3 Academic of the Medicine Course at the Central University of Paraguay
4 Academic of the Medicine Course at the Central University of Paraguay
5 Academic of the Medicine Course at the Central University of Paraguay
6 Academic of the Medicine Course at the Central University of Paraguay
7 Academic of the Medicine Course at the Central University of Paraguay
8 Academic of the Medicine Course at the Central University of Paraguay
9 Academic of the Medicine Course at the Central University of Paraguay
10 Teacher of the Medicine Course at the Central University of Paraguay
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The factors that determined the choice of this topic are supported by the fact that they are the authors
of the project, medical students where some of the colleagues were aected by covid-19 in more
severe ways and even the mildest ones such as anosmia being a sequel after the convalescence period.
It is intended to carry out exploratory research that involves a methodology with a bibliographic-
documentary survey in a systematic way on the ndings of causality between anosmia x Covid 19.
Keywords: Anosmia y Covid-19
INTRODUCTION
This article has as its theme the relationship between anosmia and covid where the interaction
between this symptom and the pathology will be outlined through the theoretical framework already
described.
On December 31, 2019, in Wuhan, a village located in China, outbreaks of atypical pneumonia
correlated with the seafood and animal market were recorded, which would later be identied as the
rst reported cases of infection with the novel coronavirus (Sars-Cov-2), a potential cause of severe
acute respiratory syndrome. The high virulence of SARS-CoV-2 combined with the great potential
for respiratory transmission, through aerosols, allowed a rapid geographical spread across continents,
characterizing it as a growing global public health problem. On March 11, 2020, the director-general
of the World Health Organization (WHO) ocially classied the contamination status as pandemic
(UNASUS, 2021).
The SARS-Cov-2 virus or simply Covid 19 entered world history in a crude and unexpected
way, it spread in the world sphere from the main urban centers to the most distant lands, reaching
the human being as a process of natural selection where the immunocompromised individuals on the
occasion of the disease did not survive.
Because it is a pathology of viral etiology, the symptomatic manifestations have varied items
and because its study is still very recent, the sequelae produced after infection by the virus are not
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clear.
The most severe forms come in the form of complications, in the form of stroke, it is congured
as a multifactorial disease, resulting in the lack of blood supply necessary to maintain the functional
mechanism of a certain area of neural tissue. It can be classied in two ways: ischemic and hemorrhagic
(Alves, THE et al, 2020), PET (pulmonary thromboembolism). Pulmonary thromboembolism is
immunologically correlated with the adaptive responses of the virus, the cause of acute PET is not
yet fully known, but may be related to endothelial injury determined by viral action and myocarditis,
direct myocardial injury consists of viral inltration into the myocardium, causing inammation and
possible death of myocytes (Nascimento JH et al, 2020). While the indirect mechanism occurs due to
severe systemic inammation, which leads to an increase in proinammatory cytokines capable of
acting on the myocardium and generating cardiovascular eects, and respiratory failure and hypoxia,
which also exert eects on the myocardium and when not treated in a timely manner and with a good
individual response, end up evolving into deaths (Clerkin KJ et al, 2020).
However, in the mild form of contagion, an aected portion has anosmia or absence of smell
as a complication, which despite the non-lethality this complication is not clear in the anatomy and
pathophysiology of the aected organ, which leads to a worsening of the quality of life of the aected
patient since smell and taste have an intrinsic relationship in human life (Pellegrini G et al, 2005).
Anosmia is dened as a partial or complete loss of smell as a result of a head injury or even
a common cold, which prevents the conduction of molecules in the air into the nasal cavities. Another
alteration that can arise is dysgeusia, which is the loss, decrease or alteration of taste. These two
symptoms can compromise the health of the individual infected with the virus (Pellegrini G et al,
2005).
Timeline of Sars-Cov2
Throughout the epidemiological history of viral diseases, we highlight the major population
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health problems caused by smallpox, yellow fever, measles, dengue, Zika, and chikungunya, which
have caused major concerns globally. Attention is currently focused on the emergence of the Sars-
cov-2 virus, the etiological agent of Covid 19, classied as a pandemic in 2020. (Nogueira JV et al,
2020)
Coronaviruses (CoV) are a broad family of viruses that can cause a variety of conditions,
from the common cold to more serious illnesses. The World Health Organization (WHO) declared on
30 January 2020 that the outbreak of the novel coronavirus (2019-nCoV) constitutes a public health
emergency of international concern (PHEIC). (PAHO, 2021)
Historically, humanity has experienced other plagues, some with repeated cycles for centuries,
such as smallpox and measles, or for decades, such as cholera. Pandemics, h1n1 inuenza in 1918,
h2n2 in 1957-58, h3n3 in 1968-69 and H5N1 in the 2000s can still be cited, known respectively as
“Spanish u”, “Asian u”, “Hong Kong u” and “avian u”, in which such names carry stigmas that
should be avoided (SOUZA, DO, 2021).
Olfactory System and Anosmia
The nose, located in the middle sole of the face, has important aesthetic and functional
aspects. Its presence is essential for the normal design of the facial urn, even if it is larger or smaller
or more or less well drawn (Virmond, 1997).
The nasal mucosa is divided into two main types: respiratory and olfactory. The airways
are thicker and heavily irrigated. It has a large number of mucous glands that secrete about a liter of
mucus a day, helping in the humidication of the air and the retention of impurities. This mucosa, due
to the large number of blood vessels, acts on the heating of the inspired air. The olfactory mucosa is
located in the area of the superior turbinate, it is thin and yellowish and carried to the cerebral cortex
for olfactory interpretation (Virmond, 1997).
The human olfactory system consists of an olfactory epithelium lining the nasal cavity, into
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which primary sensory neurons, called olfactory sensory neurons, are inserted (SILVER HDE, 2017).
The surface of the olfactory epithelium has the protruding terminals of the dendrites of
the olfactory sensory neurons, where from each protuberance emerge several immovable tabs. The
eyelashes are soaked in a layer of mucus, produced by the olfactory glands (Bowman’s glands) located
in the epithelium and in the lamina itself (SILVER HDE, 2017).
Peripheral damage caused by olfactory sensory loss, without conductive abnormalities, is
mainly secondary to viral or post-viral infections. Viral upper respiratory tract infection (URTI)
can cause olfactory dysfunction even in the absence of prior u-like symptoms, meaning that acute
anosmia may be the only symptom of a URTI. Examples of commonly involved viral agents include
rhinovirus, coronavirus, parainuenza and inuenza viruses and the Epstein-Barr virus (Gane SB et
al, 2020).
The olfactory system together with the gustatory system are essential meanings for the
human being, the loss or partiality of its functions is signicantly related to the quality of life of the
person such as diculty in activities of daily living, mood disorders, decreased appetite and problems
at work.
In addition, it is well established that the sense of smell strongly contributes to taste perception,
causing patients with anosmia to have great diculty perceiving the taste of food, thus losing appetite
and pleasure with food and as a consequence weight loss, the decrease or loss of the ability to identify
contaminated food that can cause infectious conditions (Gregorio LL, 2014).
Trauma, inammation or infections of the nervous system, degenerative diseases or congenital
malformations can be relevant factors in partial or integral, temporary or permanent anosmia in the
patient’s life.
The clinical presentation of anosmia secondary to SARS-CoV-2 is not particularly dierent
from the many other previously known causes of viral/post-viral olfactory loss. However, as acute
anosmia can also occur without any respiratory/u symptoms, it is now considered an important
symptom of SARS-CoV-2 infection, which motivates testing and even social isolation measures
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among these patients (Gane SB et al, 2020).
METHODOLOGY
This article is a descriptive-retrospective research, carried out through bibliographic and
documentary data.
Reective thinking requires a scientic treatment during research (Lakatos M, Marconi MA,
2017), where it accompanies this same line of thought, stating that research is carried out through
accessible knowledge using research methods and techniques, involving several stages. Thus, a
documentary research has the need for a systematization of data collection in order to provide concise
content in its research, and it can be a historical retrospective, or even the recording of related topics
(Gil AC, 2010).
In any scientic work, it is essential to specify the methodology and methods chosen for this
purpose. Scientic methodology is dened as the study (and use) of the methods chosen and applied
with the aim of structuring their academic work well (Creswell JW, 2007). Therefore, it is important
to present the methods previously chosen and that will provide theoretical support to this project.
“Every scientic method is a cognitive instrument that provides researchers
in any area of their training with a general orientation that facilitates the plan-
ning of research, the formulation of hypotheses, the coordination of research,
the conduct of experiments and the interpretation of results”. (Fachin, 2006)
This is a basic and systematized literature review study, using articles between 2020-2021,
which were identied through a computerized search in SciELO (http://www.scielo.org/) using the
following general descriptors: Anosmia and Covid-19. The search in the database descriptor resulted
in SciELO: 25 articles in all collections. Resulting in 10 articles from Brazil, 04 from Peru, 03 from
Argentina, 03 from Chile, 02 from Paraguay, 01 from Bolivia, 01 from Cuba, 01 from Portugal, where
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the list of anosmia and Covid was analyzed, and 08 of the articles that did not directly relate the
previous descriptors were analyzed, leaving a total of 17 studies.
CONCLUSION
Covid-19 until 2020 was a virus known to researchers, but of its real importance and
evidenced in the city of Wuhan, where the spread of SARS-COV-2 devastated the planet in one of the
largest pandemics in history, causing the planet to be directly impacted on its economies, health and
especially on society. The history of the pathology despite the short time that has elapsed since the
rst symptomatic manifestations, a line of severity or not in the sequelae left by the disease can be
observed through the investigation.
The present work, after a systematic linear analysis in documentary media, sought evidence
on the relationship of anosmia as a sequel of COVID-19.
Therefore, anosmia, being a mild complication of post-covid, its relationship is intrinsic to
the quality of life of the aected individual, which cannot be ignored during the medical analysis,
which leads us to reect on the importance of continuity through the search for scientic evidence to
clarify all the complications or their improvement against SARS COV-2, which still shows the tip of
the iceberg.
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