Kounis syndrome following COVID-19 vaccination.

Coronary stent thrombosis is a life-threatening condition induced by multiple factors, including allergic reactions. A 64-year-old man presented with stent thrombosis in the left anterior descending artery and multiple cardiorespiratory arrests immediately after the first dose of the BNT162b1 mRNA vaccine. He underwent emergent percutaneous coronary intervention. Anaphylaxis-induced stent thrombosis, or type III Kounis syndrome, is a highly possible diagnosis. Cardiogenic shock can hide the skin manifestations of anaphylaxis, making this syndrome challenging to diagnose. This clinical case underscores the importance of surveillance for at least 30 minutes after vaccine administration, especially in patients at risk.