Hymenoptera sting-induced Kounis syndrome: effects of aspirin and beta-blocker administration.

Kounis syndrome is the concurrence of acute coronary syndromes with conditions associated with activation of interacting inflammatory cells including allergic or hypersensitivity and anaphylactic or anaphylactoid insults. It is caused via inflammatory mediators released during inflammatory cell activation. A variety of conditions, drugs, and environmental exposures can induce Kounis syndrome. A patient suffering from coronary artery disease and taking metoprolol and aspirin was stung by wasps and developed cutaneous allergic signs including rash, urticaria and orbital oedema. This was followed by retrosternal pain, chest discomfort and electrocardiographic changes compatible with acute myocardial ischemia. Cardiac enzymes, troponins and blood pressure remained normal but serum tryptase was raised. The clinical implications and pathophysiology of this rare association are discussed.