Introduction:
Coronavirus disease (COVID-19) is a worldwide infection characterized by various symptoms. Few studies have examined its oral manifestations. However, there is insufficient information on the oral manifestations of patients with COVID-19 who use tobacco products. Therefore, this cross-sectional study investigated oral symptoms of tobacco-using patients with mild-to-moderate COVID-19.

Methods:
This study used a convenience sample of non-hospitalized patients (aged ≥18 years) with mild-to-moderate COVID-19 diagnosed by polymerized chain reaction (PCR). This study excluded pregnant or lactating women or patients with serious COVID-19 complications, including those who required hospitalization or were on specific medications (antiviral, corticosteroid, antimicrobial, or immunosuppressive). Oral examinations were performed, including labial, buccal, and gingival mucosa, tongue, floor of the mouth, and palate, for any newly developed lesions associated with the onset of COVID-19. The salivary flow was determined using the passive drool collection technique.

Results:
Lip dryness, gingivitis, tongue lesions, and taste loss were the most commonly reported oral symptoms in patients with mild-to-moderate COVID-19. The most common general symptoms were tiredness and headache (63.9%), followed by dry cough, myalgia, sore throat, and fever. This study found 139 occurrences of oral symptoms, of which 52 were dry lips (27 tobacco non-users, and 25 tobacco users), and 11 were gingivitis (five non-users, and six tobacco users), and 12 tongue changes (eight non-users, and four tobacco users). Ageusia, or loss of taste sensation, was most commonly reported with or without other oral COVID-19 symptoms (55 occurrences: 36 non-users and 19 tobacco users). No significant differences were found in oral symptoms between tobacco non-users and tobacco users.

Conclusions:
There is a need to expand the routine examination protocol for patients during future respiratory pandemics, as monitoring oral health allows dentists to improve the management of oral sequelae during a pandemic.