Current research shows that the damage of coronavirus to respiratory and other organs could be related to the distribution of angiotensin-converting enzyme 2 (ACE2) receptors in the human system [18]. Therefore, cells with ACE2 receptor distribution may become host cells for the virus and further cause inflammatory reactions in related organs and tissues, such as the tongue, mucosa and salivary glands. In an analysis of 49 confirmed COVID patients, Zhong and colleagues found high expression of ACE2, and a high detection rate of SARS-CoV-2 RNA in saliva [19]. Moreover, existing evidence has not established an efficient and safe pharmacological agent against COVID-19 yet, and the potential ones are related to several adverse reactions, including oral lesions. Also, COVID-19 acute infection, along with associated therapeutic measures, could potentially contribute to adverse outcomes concerning oral health, likely leading to various opportunistic fungal infections, recurrent oral herpes simplex virus (HSV-1) infection, fixed drug eruptions, dysgeusia, xerostomia linked to decreased salivary flow, ulcerations and gingivitis as a result of the weak immune system and/or susceptible oral mucosa [20, 21]. Moreover, lack of oral hygiene, stress, immunosuppression, vasculitis and hyper-inflammatory response secondary to COVID-19 are some of the major predisposing factors for oral lesions in COVID-19 positive patients [22]. Similar oral conditions were presented by our patient and others have been previously reported [9, 23].
The existing literature on oral manifestations of COVID-19 provides support for our findings, treatment administered, and the ulcer outcome. A review of more than 170 COVID-19 positive cases found changes in tongue sensation and onset of tongue ulceration to be the most common symptoms [24]. The use of photobiomodulation therapy (PBMT) in managing oral lesions has been well documented [25]. Also, the specific use of PBMT as an effective treatment in COVID-19 patients was reported by Soheilifar and colleagues [26]. Prior reporting has indicated improvements in lesion outcomes after treatment. Carreras‐Presas reported three cases of intraoral lesions that were all treated between 3 and 10 days [27].
The occurrence of oral signs and symptoms should be considered in COVID-19 patients, including dysgeusia, petechiae, candidiasis, traumatic ulcers, HSV-1 infection, geographical tongue, thrush-like ulcers, among others. Santos and colleagues reported a case of oral mucosal lesions in a COVID-19 patient [28]. Other oral manifestations of the case included recurrent herpes simplex, candidiasis, and benign migratory glossitis. The researchers posit that some oral conditions may be a result of COVID-19 treatment and for this reason, oral health professionals should be included in the clinical care team. A review of 210 COVID-19 cases which reported prone positioning and mechanical ventilation devices in the ICU as resulting in oral mucocutaneous complications reached similar conclusions [29]. Hence, the importance of the clinical examination of the oral mucosa in patients with infectious diseases in the ICU should be emphasized, considering the need for support, pain control, and quality of life. Corchuelo and colleagues report the successful use of teleconsultation as facilitating the interdisciplinary approach for a patient asymptomatic COVID-19 presenting with Candida albicans, thrush, petechiae, and melanin hyperpigmentation at the gingival level [30].
Thorough oral examination, while practicing protective measures to avoid viral transmission, is important in addressing oral manifestations of COVID-19. To that end, Bordea and colleagues report a systematic review of guidelines to provide safe and efficacious oral care during the COVID-19 pandemic [31]. A retrospective study of 47 multisystem inflammatory syndromes in children (MIS-C) positive pediatric patients, who tested positive for COVID-19 infection, concluded that dental care providers play an important role in the early detection of MIS-C and in the identification of oral lesions in MIS-C patients [32]. They posit, furthermore, that MIS-C incidence is likely to increase as the number of COVID-19 positive cases continues to grow. All things considered, oral healthcare providers can play an important role in the detection and subsequent treatment of oral manifestations following COVID-19 infection.
In conclusion, we affirm that the problems that arise in the oral mucosa in patients with suspected or confirmed SARS-CoV-2 infection should be monitored during the pandemic, as demonstrated in our case of a dorsal tongue ulcer in a COVID-19-positive patient. To prevent such an outcome, awareness programs need to be implemented for the diagnosis and management of clinical symptoms among patients.