Nonepisodic Angioedema with Eosinophilia Following Receipt of the BNT162b2 mRNA COVID-19 Vaccine

Angioedema with eosinophilia (AE) is a rare disease of unknown etiology characterized by episodic (EAE) or nonepisodic AE (NEAE). Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA-based vaccines function as immunogens and intrinsic adjuvants and have been shown to be safe in large-scale trials. However, the long-term adverse reactions, especially those related to eosinophilic complications, have not been fully clarified. We herein report a case of self-limited but severe NEAE that developed in a young woman one week after receiving the second BNT162b2 mRNA vaccine. The symptoms that impaired her activities of daily living, such as edema, gradually resolved with supportive care over 10 weeks without corticosteroid treatment.