Oral mucosal lesions in patients with COVID-19: a systematic review

COVID-19 is a new disease that presents mainly with respiratory symptoms. However, it can present with a multitude of signs and symptoms that affect various body systems and several oral manifestations have also been reported. We carried out a systematic review to explore the types of oral mucosal lesions that have been reported in the COVID-19-related literature up to 25 March 2021. A structured electronic database search using Medline, Embase, and CINAHL, as well as a grey literature search using Google Scholar, revealed a total of 322 studies. After the removal of duplicates and completion of the primary and secondary filtering processes, 12 studies were included for final appraisal. In patients with COVID-19 infection, we identified several different types of oral mucosal lesions at various locations within the oral cavity. Most of the studies appraised had a high risk of bias according to the Joanna Briggs Institute checklist. The current published literature does not allow differentiation as to whether the oral lesions were caused by the viral infection itself, or were related to oral manifestations secondary to existing comorbidities or the treatment instigated to combat the disease. It is important for healthcare professionals to be aware of the possible link between COVID-19 and oral mucosal lesions, and we hereby discuss our findings.