Lichen Planus Following COVID-19 Infection and Vaccination: Matched Case–Control Study

This matched case-control study investigated the association between COVID-19-related events and the development of new-onset lichen planus (LP). Conducted at the National Research Center of Dermato-Venereology of Moscow, the study included 55 case-control pairs matched by sex, age, and ethnicity. The results showed a significant association between COVID-19 infection/vaccination and de novo LP, with odds ratios of 7.50 and 4.45 for conditional and unconditional analyses, respectively. Subgroup analysis confirmed the link between symptomatic COVID-19 infection and LP, while sensitivity analysis supported the primary findings. The study suggests that COVID-19-related events, particularly infection, may trigger LP.