ABSTRACT
The coronavirus disease 2019 (Covid-19) is a viral infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that clinically affects multiple organs of the human body. Cells in the oral cavity express viral entry receptor angiotensin-converting enzyme 2 that allows viral replication and may cause tissue inflammation and destruction. Recent studies have reported that Covid-19 patients present oral manifestations with multiple clinical aspects. In this review, we aim to summarise main signs and symptoms of Covid-19 in the oral cavity, its possible association with oral diseases, and the plausible underlying mechanisms of hyperinflammation reflecting crosstalk between Covid-19 and oral diseases. Ulcers, blisters, necrotising gingivitis, opportunistic coinfections, salivary gland alterations, white and erythematous plaques and gustatory dysfunction were the most reported clinical oral manifestations in patients with Covid-19. In general, the lesions appear concomitant with the loss of smell and taste. Multiple reports show evidences of necrotic/ulcerative gingiva, oral blisters and hypergrowth of opportunistic oral pathogens. SARS-CoV-2 exhibits tropism for endothelial cells and Covid-19-mediated endotheliitis can not only promote inflammation in oral tissues but can also facilitate virus spread. In addition, elevated levels of proinflammatory mediators in patients with Covid-19 and oral infectious disease can impair tissue homeostasis and cause delayed disease resolution. This suggests potential crosstalk of immune-mediated pathways underlying pathogenesis. Interestingly, few reports suggest recurrent herpetic lesions and higher bacterial growth in Covid-19 subjects, indicating SARS-CoV-2 and oral virus/bacteria interaction. Larger cohort studies comparing SARS-CoV-2 negative and positive subjects will reveal oral manifestation of the virus on oral health and its role in exacerbating oral infection.
Subject(s)
COVID-19/complications , Gingivitis, Necrotizing Ulcerative/complications , Herpesviridae Infections/complications , Oral Ulcer/complications , Periodontal Diseases/complications , Sialadenitis/complications , Stomatitis, Aphthous/complications , Xerostomia/complications , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/immunology , Anosmia/complications , Anosmia/immunology , Anosmia/pathology , Anosmia/virology , COVID-19/immunology , COVID-19/pathology , COVID-19/virology , Dysgeusia/complications , Dysgeusia/immunology , Dysgeusia/pathology , Dysgeusia/virology , Gene Expression , Gingivitis, Necrotizing Ulcerative/immunology , Gingivitis, Necrotizing Ulcerative/pathology , Gingivitis, Necrotizing Ulcerative/virology , Herpesviridae Infections/immunology , Herpesviridae Infections/pathology , Herpesviridae Infections/virology , Humans , Mouth/immunology , Mouth/pathology , Mouth/virology , Oral Ulcer/immunology , Oral Ulcer/pathology , Oral Ulcer/virology , Periodontal Diseases/immunology , Periodontal Diseases/pathology , Periodontal Diseases/virology , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Serine Endopeptidases/genetics , Serine Endopeptidases/immunology , Sialadenitis/immunology , Sialadenitis/pathology , Sialadenitis/virology , Stomatitis, Aphthous/immunology , Stomatitis, Aphthous/pathology , Stomatitis, Aphthous/virology , Xerostomia/immunology , Xerostomia/pathology , Xerostomia/virologyABSTRACT
Coronavirus disease 2019 (COVID-19) is a new disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. China reported the first case of COVID-19 in December 2019, and a few months later, the World Health Organization declared it as a pandemic. Oral ulcers in adult patients have been associated with COVID-19. However, no cases have yet been documented in children. The angiotensin-converting enzyme-2 (ACE2) receptor has been identified in tissues of the oral cavity. Studies have identified the tongue as the site with the highest expression of ACE2, and the oral epithelium, gingival epithelium, and salivary glands as sites of lesser extent expression. ACE2 expression is lower in children and varies with age. SARS-CoV-2 in saliva has been identified in various studies, which suggests that this could be a useful sample for diagnosis. However, its presence in saliva would indicate the high risk of contagion of this fluid.