mRNA COVID-19 Vaccine-Associated Subserosal Eosinophilic Gastroenteritis: A Case Report

The World Health Organization declared coronavirus disease 2019 (COVID-19) a global pandemic in March 2020. Several vaccines have been developed to overcome the COVID-19 pandemic, and messenger RNA vaccines, commonly known as mRNA vaccines, were the first COVID-19 vaccines to be authorized in Korea. With the worldwide increase in vaccinations, reports of adverse reactions are increasing. However, to the best of our knowledge, there have been no reports of eosinophilic gastroenteritis (EGE) following mRNA vaccination. Here, we present the first case of EGE in a patient who received a second dose of the mRNA vaccine, BNT162b2 (Pfizer-BioNTech). A previously healthy 34-year-old woman presented to the emergency department with generalized abdominal pain for the preceding 2 weeks. She had received a second dose of the mRNA COVID-19 vaccine 2 weeks prior. Subserosal EGE was diagnosed, oral prednisolone was administered, and she recovered completely.