This document is a letter to the editor discussing a study conducted in Moscow, Russia, between September 2020 and December 2022. The study investigated the association between COVID-19 infection or vaccination and the development of pemphigus vulgaris (PV) and pemphigus foliaceus (PF). The study found that COVID-19-related antigenic challenges were associated with the development of PV and PF, suggesting a possible causal relationship. However, the authors note that this is the first observational study on the topic and further research is needed to confirm these findings. [Extracted from the article]