Lichen planus flare following COVID‐19 vaccination: A case report

Abstract We report the third case of cutaneous lichen planus (LP) following COVID‐19 BNT162b2 vaccination in a 59‐year‐old woman with previous LP. The reactivation of LP in patients with dormant LP suggests a possible vaccine‐induced immune dysregulation. We suggest that the already described vaccine‐induced upregulation of Th1 response may play a relevant role in LP reactivation, through an increase in inflammatory cytokines involved in the pathogenesis of LP. Interestingly, LP has already been associated with vaccinations and viral infections including COVID‐19 disease. However, the exact mechanism underlying LP (re)activation after Pfizer‐BiotNtech COVID‐19 vaccination is still widely unknown and needs to be further investigated.