Since its emergence, coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread worldwide, leaving an indelible mark on human health.
As of October 1, 2022, the global impact of this pandemic has been staggering, with over 617.7 million confirmed cases and more than 6.5 million deaths, according to data from the Johns Hopkins University Coronavirus Resource Center .
Over the course of three years, our understanding of COVID-19 has evolved significantly, revealing a spectrum of clinical manifestations that extend beyond the respiratory system.
While fever, cough, and dyspnea have commonly characterized the acute phase of the disease, it has become increasingly evident that the long-term effects or sequelae of COVID-19 encompass a broader range of symptoms, including those related to oral tissues and functions.
Oral Manifestations of COVID-19
In addition to the more recognizable symptoms, COVID-19 patients have been reported to experience a variety of oral manifestations.
These include impairments of taste such as ageusia (complete taste loss) and dysgeusia (impaired taste), which can be further classified into severe, moderate, and mild hypogeusia (or amblygeustia).
Furthermore, disturbances in saliva secretion have also been observed, leading to conditions such as dry mouth, xerostomia (subjective complaint of oral dryness), and hyposalivation (objective reduction of salivary flow rates) [2, 3].
While these oral symptoms may not be life-threatening, their persistence can significantly impact the quality of life of COVID-19 survivors who have otherwise recovered from the acute phase of the disease.
Long-Term Effects and Sequelae
As the pandemic has progressed, attention has shifted towards understanding the long-term effects of COVID-19, often referred to as sequelae. These effects can persist even after the resolution of acute symptoms, leading to ongoing challenges for those who have battled the virus.
Studies have shown that a substantial number of COVID-19 survivors continue to experience symptoms beyond the acute phase. In fact, a follow-up study conducted after two months from symptom onset revealed that 87.4% of survivors reported at least one persistent symptom, with 55% of them experiencing three or more sequelae .
Among these long-term effects, symptoms such as fatigue, headache, attention disorder, neurocognitive disorder (commonly referred to as “brain fog”), cough, dyspnea, and hair loss have been frequently documented .
Terminology and Timeframes
Despite the recognition of long-term effects, a standardized terminology and timeframe for assessing these sequelae in COVID-19 patients are lacking. Various definitions have been proposed to categorize these effects. Greenhalgh et al.  defined post-acute COVID-19 as persisting beyond three weeks from symptom onset, while chronic COVID-19 was described as extending beyond 12 weeks. Given the recovery timeline of chemosensory disorders, effects lasting more than three weeks can be considered as COVID-19 sequelae, encompassing a range of physiological changes that impact patients’ well-being.
Characterizing Oral Sequelae
While there has been extensive research on COVID-19 symptoms in the acute phase, understanding of post-COVID-19 oral symptoms remains relatively limited in comparison. Gustatory and saliva secretory dysfunctions, though not life-threatening, have a substantial impact on the overall quality of life for survivors. As the population of COVID-19 survivors continues to grow, it becomes increasingly crucial to expand our knowledge of the oral sequelae of the disease and their underlying pathophysiological mechanisms.
The ongoing battle against the COVID-19 pandemic has highlighted the multifaceted nature of the disease, extending beyond the respiratory system to affect various bodily functions, including oral health.
While the acute phase of COVID-19 has been characterized by fever, cough, and dyspnea, the long-term effects, or sequelae, encompass a broader spectrum of symptoms, including those related to taste and saliva secretion.
As we continue to navigate this evolving landscape, it is imperative to deepen our understanding of these oral sequelae and their pathogenic mechanisms to better support the growing population of COVID-19 survivors.
By doing so, we can strive to improve the quality of life for those who have triumphed over the virus while grappling with its enduring impact.
reference link : https://karger.com/mpp/article/doi/10.1159/000531373/844623/COVID-19-Oral-Sequelae-Persistent-Gustatory-and?searchresult=1