Abstract
BACKGROUND: Acute pericarditis is a diffuse inflammation of the pericardial sac with many well-defined etiologies. Acute pericarditis as a vaccine-related adverse event is a rare entity, and the association between pericarditis and the immunogenic response to Coronavirus disease 2019 (COVID-19) vaccines is still being fully characterized. CASE REPORT: A previously healthy 18-year-old man presented with fever, pleuritic chest pain, and shortness of breath 3 weeks after receiving the first dose of a COVID-19 mRNA-based vaccine. The patient was found to have a large pericardial effusion with early tamponade physiology requiring pericardiocentesis. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: As COVID-19 vaccination becomes more prevalent globally, physicians should be aware of pericarditis as a rare but potentially serious adverse reaction. Although a direct causal link cannot be demonstrated, we present this case to increase awareness among emergency physicians of pericarditis as a rare, but potentially serious adverse event associated with COVID-19 vaccination.