SynthesisBrazilian journal of otorhinolaryngology
Pathophysiological relationship between COVID-19 and olfactory dysfunction: A systematic review.
Synthesis in Brazilian journal of otorhinolaryngology. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 29 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
29 citing papers in PubMed, 1 synthesis or guideline pooled it, 42 citations in OpenAlex.
- Brain MRI findings in neurologically symptomatic COVID-19 patients: a systematic review and meta-analysis.Journal of neurology · 2023Pooled it
- Olfactory Training for COVID-19-Related Olfactory Dysfunction: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.Turkish archives of otorhinolaryngology · 2026Article
- Review
- COVID-19 infection and longitudinal changes in olfactory-related brain structures in children: analysis of ABCD study data.European journal of pediatrics · 2025Observational
- Viral Etiologies and Histopathological Features of Olfactory Dysfunction: A Systematic Review.Health science reports · 2025Review
- Neurological Impact of SARS-CoV-2 Changing Variants: A 4-Year DW-MRI Study on Olfactory and Taste-Related Brain Regions.International journal of molecular sciences · 2025Article
- Observational
- SARS-CoV-2-Related Olfactory Dysfunction: Autopsy Findings, Histopathology, and Evaluation of Viral RNA and ACE2 Expression in Olfactory Bulbs.Biomedicines · 2024Article
- COVID-19 and Alzheimer's disease: Impact of lockdown and other restrictive measures during the COVID-19 pandemic.Biomolecules & biomedicine · 2024Review
- Article
- Global research Activity on olfactory marker protein (OMP): A bibliometric and visualized analysis.Heliyon · 2024Article
- Prevalence and Factors Associated with Olfactory Dysfunction in Individuals with COVID-19 in Brazil: A Study of 20,669 Cases from 2020 to 2021.Medical principles and practice : international journal of the Kuwait University, Health Science Centre · 2024Article
- Inflammation and olfactory loss are associated with at least 139 medical conditions.Frontiers in molecular neuroscience · 2024Article
- Intranasal Insulin for Treatment of Persistent Post-COVID-19 Olfactory Dysfunction: A Scoping Review.Journal of community hospital internal medicine perspectives · 2024Article
- Pathogenesis and progression of anosmia and dysgeusia during the COVID-19 pandemic.European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery · 2023Review
- 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.Journal of clinical medicine · 2023Article
- Neuropsychiatric consequences of COVID-19 related olfactory dysfunction: could non-olfactory cortical-bound inputs from damaged olfactory bulb also contribute to cognitive impairment?Frontiers in neuroscience · 2023Article
- The immune mechanism of the nasal epithelium in COVID-19-related olfactory dysfunction.Frontiers in immunology · 2023Review
- Effects of nasal inflammation on the olfactory bulb.Journal of neuroinflammation · 2022Review
- Olfactory dysfunction in COVID-19, new insights from a cohort of 353 patients: The ANOSVID study.Journal of medical virology · 2022Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
3 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
introductionSARS-CoV-2 is the pathogen of COVID-19. The virus is composed of the spike, membrane and envelope. On physiological smell, odoriferous substances bind to proteins secreted by sustentacular cells in order to be processed by olfactory receptor neurons. Olfactory disorder is one of the main manifestations of COVID-19, however, research is still required to clarify the mechanism involved in SARS-CoV-2 induced anosmia.
objectiveThis article aims to analyze current scientific evidence intended to elucidate the pathophysiological relationship between COVID-19 and the cause of olfactory disorders.
methodsPubmed, Embase, Scopus and ScienceDirect were used to compose this article. The research was conducted on November 24th, 2020. Original articles with experimental studies in human, animal and in vitro, short communications, viewpoint, published in the English language and between 2019 and 2020 were included, all related to the pathophysiological relationship between olfactory disorders and COVID-19 infection.
resultsBoth human cell receptors ACE2 and TMPRSS2 are essential for the SARS-CoV-2 entrance. These receptors are mostly present in the olfactory epithelium cells, therefore, the main hypothesis is that anosmia is caused due to damage to non-neuronal cells which, thereafter, affects the normal olfactory metabolism. Furthermore, magnetic resonance imaging studies exhibit a relationship between a reduction on the neuronal epithelium and the olfactory bulb atrophy. Damage to non-neuronal cells explains the average recovery lasting a few weeks. This injury can be exacerbated by an aggressive immune response, which leads to damage to neuronal cells and stem cells inducing a persistent anosmia. Conductive anosmia is not sufficient to explain most cases of COVID-19 induced anosmia.
conclusionOlfactory disorders such as anosmia and hyposmia can be caused by COVID-19, the main mechanism is associated with olfactory epithelium damage, targeting predominantly non-neuronal cells. However, neuronal cells can also be affected, worsening the condition of olfactory loss.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.