Oral Lesions Associated with COVID-19 and the Participation of the Buccal Cavity as a Key Player for Establishment of Immunity against SARS-CoV-2

Oral lesions with immunohistochemical evidence of Sars-CoV-2 in swab-negative post-COVID syndrome

OBJECTIVES

Growing evidence exists about post-COVID condition/syndrome as sequelae of Sars-CoV-2 infection in healed patients, possibly involving the lungs, brain, kidney, cardiovascular and neuromuscular system, as well the persistency of taste dysfunction. Such symptoms develop during or after infection and continue for more than 12 weeks with pathogenesis related to virus persistency but variable by organs or systems.

MATERIALS AND METHODS

We recently observed six patients recovered from COVID-19 and with negative RT-PCR testing, showing oral mucosa lesions (mainly ulcers) overlapping those occurring in the acute phase, persisting up to 20 days and thus needing a biopsy with histological investigation and spike protein evaluation by immunohistochemistry.

RESULTS

We found epithelial ulceration, inflammatory infiltrate, vessels with increased diameter and flattened endothelium but no thrombi formation; also, we found a weak epithelial SARS-CoV-2 positivity limited to the basal/spinosum layers, progressively decreasing toward the periphery, and the intraepithelial lymphomonocytes, endothelium, and perivascular pericytes too.

CONCLUSIONS

Our findings provide evidence that SARS-CoV-2 can persist, as for other organs/systems, also in the oral epithelium/mucosa after the acute phase and can be responsible for lesions, although by a pathogenetic mechanism that should be better defined but certainly referable as the oral mucosa counterpart of post-COVID syndrome.

Vascular cutaneous manifestations of COVID-19 and RNA viral pathogens: a systematic review

BACKGROUND

COVID-19, the widely recognized and highly contagious respiratory tract infection, has had a substantial impact on the field of dermatology since its emergence in 2019. SARS-CoV-2, the causative virus of COVID-19, is classified as an RNA virus. Various skin-related symptoms have been reported in patients with COVID-19, most notably the distinctive purple-red acral rash resembling chilblain lesions, commonly referred to as 'COVID toe'; similarly, skin-related symptoms have been observed in connection with other RNA viruses.

OBJECTIVES

To explore the relationship between RNA viruses and their associated vascular cutaneous manifestations vs. those observed in patients infected with SARS-CoV-2.

METHODS

A systematic literature review was conducted using PubMed and medical subject heading terms related to RNA viruses and related skin manifestations.

RESULTS

In total, 3994 patients diagnosed with COVID-19 presenting with skin rashes were included. Chilblain-like lesions were most frequently observed (30.2%), followed by erythematous maculopapular/morbilliform rashes (9.1%) and urticarial rashes (4.7%). Of 8362 patients diagnosed with RNA viruses, more than half of the skin findings reported were erythematous/maculopapular/morbilliform rashes (52.3%), followed by unspecified (11.3%) and purpuric rashes (10.6%).

CONCLUSIONS

When comparing RNA viral infections with COVID-19 infection, we observed similarities in the reported skin manifestations and their presumed pathways, with many implicated in the proinflammatory response. Owing to the wide range of cutaneous symptoms associated with RNA viruses and our currently limited understanding of the underlying mechanisms, additional research is warranted to investigate the pathology behind viral-induced skin lesions.

Pathological changes in oral epithelium and the expression of SARS-CoV-2 entry receptors, ACE2 and furin

BACKGROUND

Expression of angiotensin-converting enzyme (ACE)-2 and co-factors like furin, play key-roles in entry of SARS-CoV-2 into host cells. Furin is also involved in oral carcinogenesis. We investigated their expression in oral pre-malignant/malignant epithelial pathologies to evaluate whether ACE2 and furin expression might increase susceptibility of patients with these lesions for SARS-CoV-2 infection.

METHODS

Study included normal oral mucosa (N = 14), epithelial hyperplasia-mild dysplasia (N = 27), moderate-to-severe dysplasia (N = 24), squamous cell carcinoma (SCC, N = 34) and oral lichen planus (N = 51). Evaluation of ACE2/furin membranous/membranous-cytoplasmic immunohistochemical expression was divided by epithelial thirds (basal/middle/upper), on a 5-tier scale (0, 1-weak, 1.5 -weak-to-moderate, 2-moderate, 3-strong). Total score per case was the sum of all epithelial thirds, and the mean staining score per group was calculated. Real time-polymerase chain reaction was performed for ACE2-RNA. Statistical differences were analyzed by One-way ANOVA, significance at p<0.05.

RESULTS

All oral mucosa samples were negative for ACE2 immuno-expression and its transcripts. Overall, furin expression was weakly present with total mean expression being higher in moderate-to-severe dysplasia and hyperplasia-mild dysplasia than in normal epithelium (p = 0.01, each) and SCC (p = 0.008, p = 0.009, respectively).

CONCLUSIONS

Oral mucosa, normal or with epithelial pathologies lacked ACE2 expression. Furin was weak and mainly expressed in dysplastic lesions. Thus, patients with epithelial pathologies do not seem to be at higher risk for SARS-CoV-2 infection. Overall, results show that oral mucosae do not seem to be a major site of SARS-CoV-2 entry and these were discussed vis-à-vis a comprehensive analysis of the literature.

Insights into estrogen impact in oral health & microbiome in COVID-19

BACKGROUND

COVID-19 emerged in late 2019 and has occasioned more than 765 millions cumulative cases and 6.9 millions of deaths globally. Notably, around 70% of patients with severe COVID-19 are men. Therefore, it is to be presumed that women have a hormonal protector factor in inflammation and ACE2 expression. On the other hand, oral health status, and local microbiome can be key factors to respiratory viral infections control. Nevertheless, it has been poorly investigated. In our study 20 premenopausal, 18 postmenopausal and 22 men with COVID-19 were included. Oral health status, viral load, lingual ACE2 expression, as well as microbiome, estrogens and cytokines in saliva were analyzed.

RESULTS

Our results showed a lower expression of ACE2 in tongue cells of postmenopausal compared with premenopausal (p = 0.05), and a strong negative correlation between saliva estrogen and viral load (r = -0.76; p = 0.001). Respect to IFN-γ (p = 0.05), IL-1β, TNF-α, IL-18, and IL-23 levels were increased in postmenopausal. Oral microbiome signature of premenopausal was characterized by Prevotella melaninogenica (Log2 = 26.68; p = 1.34e-10), Haemophilus (Log2 = 23.99; p = 2.96e-9), and Alloprevotella (Log2 = 7.92; p = 0.0001). On the other hand, Leptotrichia (Log2 = -18.74; p = 0.001), Tanerella (Log2 = -17.08; p = 0.004), and Clostridiales (Log2 = -2.88; p = 0.04) represented the poor oral health group compared with the adequate group which was enriched with the commensal microorganism Neisseria perflava (Log2 = 26.70; p = 1.74e-7). Furthermore, the high viral load group was characterized by Prevotella nanceiensis (Log2 = 19.60; p = 6.06e-8), Prevotella melaninogenica (Log2 = 21.45; p = 9.59e-6), Alloprevotella (Log2 = 23.50; p = 2.70e-7) and bacteria from the red complex Porphyromonas endodentalis (Log2 = 21.97; p = 1.38e-7).

CONCLUSIONS

Postmenopausal and men have a poor oral health status which could be related to a detrimental progression of COVID-19 also linked to a lower expression of ACE2, lower saliva estrogen levels and oral dysbiosis. Nevertheless, functional studies are required for a deeper knowledge.

A reflection on COVID-19 and oral mucosal lesion: a systematic review

Introduction

The aim of this systematic review is to provide a clinical update of the current knowledge on COVID-19 and oral mucosal lesions, to analyze the types and prevalence of oral mucosal lesions in patients with COVID-19, and to clarify the potential association between COVID-19 and oral mucosal lesions.

Methods

The literature search was conducted using PubMed, Web of Science, Scopus and the Cochrane Library, as well as literatures via manual searches of the reference lists of included studies. Studies published in English that mentioned oral mucosal lesions in patients with COVID-19 were included, resulting in a total of 31 studies.

Results

Most of the included studies were considered to have a moderate to high risk of bias according to the Joanna Briggs Institute bias assessment tools. Based on COVID-19 severity, the characteristics and patterns of oral mucosal lesions in COVID-19 patients were described, analyzed and synthesized. Overall, ulcers without specific diagnosis had the highest prevalence in COVID-19 patients, followed by traumatic ulcers, candidiasis, petechiae and aphthous-like lesions. Homogeneity of data cannot be achieved in statical analysis, indicating randomness of outcome (ulcers without specific diagnosis, 95% CI: 28%-96%, I2 = 98.7%).

Discussion

Given the limited evidence from currently available studies, the association between COVID-19 and oral mucosal lesions remains difficult to clarify. Healthcare professionals should be aware of the possible association between COVID-19 and oral mucosal lesions, and we hereby discuss our findings.

Awareness of undergraduate dental students, interns, and freshly graduated dentists about oral manifestation associated with COVID-19

OBJECTIVE

There is growing evidence supporting the presence of oral manifestations associated with COVID-19. The study investigates the knowledge of dental undergraduates and recently graduated dentists concerning oral presentations related to COVID-19.

METHODS

A cross-sectional descriptive study in Saudi Arabia comprised 305 individuals, including undergraduate dental students, interns, and freshly graduated dentists. Data were collected using a questionnaire disseminated to approximately 500 subjects via WhatsApp groups and other applications. The questionnaire was tested in a pilot study for validity, edited, and validated by 2 supervisors at the College of Dentistry, Qassim University, Buraydah, Saudi Arabia. The questionnaire consisted of questions regarding sociodemographic attributes, the level of expertise of dental practitioners, and their knowledge and perspectives regarding COVID-19 and the implementation of oral lesions interrelated to it. The data was subjected to analysis through the utilization of descriptive statistics and chi-square tests, employing the statistical software SPSS (version 24).

RESULTS

About 43.9% of subjects stated that COVID-19 causes oral symptoms. Respondents most frequently reported COVID-19-related dry mouth. Oral ulcers, Candida infection, Hyperpigmentation, tongue coating, atrophy, Petechiae, Herpes, white lesions, Gingivitis, and Periodontitis are further symptoms. COVID-19's oral manifestation was unknown to 41.0% of subjects, and 37.7% of respondents lacked knowledge regarding the most impacted locations of oral manifestations. Oral signs and COVID-19 symptoms are debated and significantly associated with higher educational levels.

CONCLUSION

The dental students and freshly graduated dentists in this study have proper knowledge of COVID-19 and its symptoms. Also, most dental students and newly graduated dentists recognize the potential correlation between COVID-19 and oral manifestations with an average to excellent knowledge of the types and sites commonly affected. The level of awareness was associated with higher educational levels.

Oral manifestations of COVID-19 in unvaccinated patients: a cross-sectional study

BACKGROUND

Early studies have highlighted the possible development of dysgeusia and anosmia in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and these manifestations should be considered a potential indication of coronavirus disease 19 (COVID-19). As potential contributors to these symptoms, dentists should perform careful oral and oropharyngeal examinations and document suspicious oral lesions in patients with COVID-19, especially in those who complain of loss of taste and smell. The study's objective was to assess the prevalence of oral manifestations among ambulatory unvaccinated symptomatic patients with suspected COVID-19 during the acute phase of the disease.

METHODS

This cross-sectional study evaluated oral manifestations in adults (aged ≥ 18 years) with suspected and confirmed SARS-CoV-2 infection. Chi-square and Fisher's exact tests were used to compare data between the groups (rRT-PCR-positive and rRT-PCR-negative patients).

RESULTS

One hundred thirty-six participants were included. Most were female (n = 79; 58.1%), with a mean age of 39.53 (± 14.17) years. Of these, 54 (39.7%) had a positive rRT-PCR test, and 82 (60.3%) had negative rRT-PCR results. Oral manifestations were observed in 40 participants (74.1%) in the rRT-PCR-positive group and 67 participants (81.7%) in the rRT-PCR-negative group. The most common oral manifestations were xerostomia (n = 85; 62.5%) and dysgeusia/ageusia (n = 57; 41.9%). Different rates of gingivitis (n = 12; 22.2% vs. n = 5; 6.1%; p = 0.005) and halitosis (n = 7; 13.0% vs. n = 1; 1.2%; p = 0.007) were observed between the rRT-PCR-positive and -negative groups, respectively. Mouth ulcers, glossitis, tongue coating, and petechiae were reported in both groups without significant differences.

CONCLUSIONS

A high prevalence of oral manifestations was observed in symptomatic patients with suspected or confirmed COVID-19.

CLINICAL RELEVANCE

This study highlights the importance of routine oral examinations by dentists as part of the multidisciplinary care of COVID-19 patients.