Chronic oral diseases secondary to COVID-19 infection or vaccination: clinical cases and a narrative review.

Objectives: Autoimmune activation by COVID-19 infection/vaccination has been postulated to be responsible for initiating or reactivating multiple types of oral mucosal immune disorders. These include: oral lichen planus; oral pemphigoid; either bullous pemphigoid or mucous membrane pemphigoid with oral involvement; pemphigus vulgaris with oral involvement; and Sjögren disease. In addition, chronic conditions such as oral burning, xerostomia, or changes in taste and/or smell have also been linked to COVID-19 infection/vaccination.

Data sources: Part 1 (mucosal conditions): an English-language literature review of Pubmed, Web of Science, Scopus, and Embase was performed searching cases of oral lichen planus, oral bullous pemphigoid, mucous membrane pemphigoid, pemphigus vulgaris, and COVID-19 infection/vaccination, with additional cases from the authors' clinical practice presented. Part 2 (nonmucosal conditions): Cases of initiated or flared Sjögren disease, chronic oral burning, or xerostomia after COVID-19 infection/vaccination from the authors' clinical practice were aggregated.

Results: The literature review discovered 29 cases of oral lichen planus following COVID-19 infection/vaccination. For bullous pemphigoid, 10 cases were identified after infection/vaccination. The number of pemphigus vulgaris cases following infection/vaccination was 28. The majority of mucosal cases were reported after vaccination. Most reported initial disease, but a substantial amount included recurrences of existing diseases. Nonmucosal disease: Sjögren disease, chronic oral burning, or xerostomia after COVID-19 infection/vaccination cases totaled 12 cases identified from the authors' clinical practice, with the majority occurring after infection.

Conclusions: Chronic conditions after infection with COVID-19 or vaccination remain relatively rare and self-limited, yet reinforce the importance of comprehensive history taking involving COVID-19 to differentiate potential etiologic factors for these conditions.