Current evidence on possible oral manifestations of SARS-CoV-2 infection.

Dear Editor,

The recently published article entitled “Oral vesiculobullous lesions associated with SARS‐CoV‐2 infection,” by Martín et al. (2020), has been widely discussed among the dentistry community. This is the first description presented in the scientific literature aimed exclusively at oral lesions associated with the new coronavirus (SARS‐CoV‐2), the infectious agent responsible for the COVID‐19 pandemic. At the same time, larger studies on cutaneous manifestations related to this respiratory syndrome have also referred to the occurrence of changes in the oral mucosa. However, they present less detailed information (Galván Casas et al., 2020; Tang et al., 2020; Jimenez‐Cauhe et al., 2020; Hedou et al., 2020).

Martín et al. (2020) presented three cases of oral lesions associated with SARS‐CoV‐2 infection, in which only one patient had a confirmed diagnosis of coronavirus infection. Also, according to the authors, individuals were not assessed personally due to the state of alarm, and the diagnosis was conducted through clinical history and images sent by the patients. No additional tests were performed to confirm the diagnosis or exclude differential diagnoses.

The clinical presentations of two of the three described cases are characterized by multiple ulceration areas on the hard palate, lesions typically seen in cases of intraoral herpes simplex virus (HSV‐1) infection. The authors emphasized the similarity of the lesions with HSV‐1 manifestations and described other aspects that corroborate the probable differential diagnosis such as emotional distress and the presence of signs of previous infection and immune impairment. Importantly, other authors have already presented evidence of reactivation of the HSV‐1 in COVID‐19 patients (Tang et al., 2020; Hedou et al., 2020). Dermatologists have also observed an increase in the number of cases of herpes zoster in individuals infected with SARS‐CoV‐2 (Galván Casas et al., 2020). Therefore, the appearance of the lesions observed in the present study cannot be considered pathognomonic. Quite to the contrary, this condition is commonly observed in several pathological processes of the oral mucosa, especially those associated with viral infections.

In the third patient, the lesions affected the skin and both the keratinized and non‐keratinized mucosa and were described by the authors as compatible with oral/cutaneous manifestations of erythema multiforme (EM). The similarity between the patterns of cutaneous manifestations of EM and COVID‐19 infection has also been observed previously, and they have been described as erythema multiforme‐like lesions (Jimenez‐Cauhe et al., 2020). It is important to note that EM is linked to infectious agents or a drug‐induced hypersensitivity reaction, and both aspects could have occurred in the third case.

In conclusion, there is consensus in the scientific community that the oral cavity can show signs of several systemic diseases, as well as reactions to external agents. To date, the level of scientific evidence is insufficient to support the characterization of a specific, or even a non‐specific, COVID‐19 oral manifestation. Thus, at this moment it is difficult to affirm that the occurrence of oral lesions is directly related to COVID‐19. Further studies and accurate investigations are needed to confirm whether the lesions are associated with the SARS‐CoV‐2 virus or other oral viral infections, such as HSV‐1, with drug‐induced hypersensitivity reactions, or with any other condition of immune impairment.

CONFLICT OF INTEREST

The authors declare that they have no competing interests.

AUTHOR CONTRIBUTIONS

Amanda Rocha: Conceptualization; Writing–original draft. Alessandra Figueiredo Souza: Conceptualization; Writing–review & editing. Renata Gonçalves Resende: Conceptualization; Supervision; Writing–review & editing.