Type III Kounis Syndrome Caused by Iodine Contrast Media After Improvement of Allergic Symptoms.

Kounis syndrome is an acute coronary syndrome (ACS) caused by an allergic reaction that almost always occurs immediately and simultaneously with allergic symptoms. We present a case of Kounis syndrome type III that developed after complete resolution of contrast-induced anaphylaxis in a 60-year-old man with a coronary stent placed in the proximal left anterior descending (LAD) artery branch for ischemic heart disease. Contrast-enhanced computed tomography revealed anaphylactic shock. Symptoms quickly improved with intramuscular adrenaline injection; however, chest pain appeared after approximately 30 min. ECG revealed ST-wave elevation in the precordial leads. Coronary angiography revealed acute stent thrombosis with total occlusion of the proximal LAD, and percutaneous coronary angioplasty was performed. We diagnosed Kounis syndrome based on the allergic symptoms and ACS. Because some cases of Kounis syndrome develop after anaphylactic symptoms have resolved, it is advisable to follow-up patients with allergic symptoms and pay attention to chest symptoms and ECG changes, especially when they have a history of noted or treated coronary artery disease.