Kounis Syndrome Without Systemic Allergy: A Subtle Presentation of Stent Thrombosis

Kounis Syndrome, or allergic acute coronary syndrome, is a rare cause of myocardial ischemia triggered by hypersensitivity reactions. Type III Kounis Syndrome, involving in-stent thrombosis following an allergic insult, is particularly rare and underrecognized. We report the case of a 67-year-old woman with a known contrast allergy who developed inferior ST-elevation myocardial infarction (STEMI) complicated by early stent thrombosis, suspected to be due to type III Kounis Syndrome. This case underscores the importance of maintaining a high index of suspicion for allergic triggers in acute coronary syndromes and considering contrast-sparing strategies in high-risk individuals.