Three cases of drug-induced hypersensitivity syndrome associated with mRNA-based coronavirus disease 2019 vaccines.

Drug-induced hypersensitivity syndrome (DiHS) is a severe drug eruption that can induce reactivation of herpesviruses such as human herpesvirus 6, resulting in symptom flare-up and organ damage. DiHS is known as drug reaction with eosinophilia and systemic symptoms (DRESS) in Europe. We report three cases of DiHS that could have been triggered by mRNA-based coronavirus disease 2019 (COVID-19) vaccines. In these three patients, symptoms of DiHS developed 2-6 days after the first dose of an mRNA-based COVID-19 vaccine. Although there have been no reports of DiHS/DRESS induced by mRNA-based COVID-19 vaccines in domestic and international journals despite the progress in vaccination worldwide, we speculate that mRNA-based COVID-19 vaccines might have triggered the development of DiHS/DRESS in our patients. In the current coronavirus epidemic, it might be important to assess mRNA-based COVID-19 vaccination status and date of vaccination when evaluating a patient with DiHS/DRESS.