RESUMEN
BACKGROUND: The occurrence of acute ischaemia or myocardial infarction in a patient experiencing an allergic reaction is known as allergic acute coronary syndrome or Kounis syndrome. CASE DESCRIPTION: A 63-year-old male had a postoperative anaphylactic reaction to an intravenous dose of diclofenac. Myocardial ischaemia occurred during treatment of the anaphylaxis, caused by spasm of the right coronary artery followed by occlusion of the left anterior descending artery (the ramus interventricularis anterior). Despite percutaneous coronary intervention, he suffered an infarct of the anterior myocardium, resulting in reduced left ventricular function. CONCLUSION: In patients with Kounis syndrome therapy should focus on both the allergy and the acute coronary syndrome. Early recognition and intervention have a great effect on prognosis.