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.
Keywords: SARS-CoV-2; COVID-19; Angiotensin-converting enzyme II; Children.