• Definitions
  1. Kounis Syndrome
    1. Acute Coronary Syndrome triggered by an Allergic Reaction
  • Epidemiology
  1. Seen in ~1% of patients admitted with Allergic Reaction
  • Pathophysiology
  1. First described in 1991 by Nicholas Kounis
  2. Allergic Reaction cascade involving Mast Cell activation, Histamine release and Platelet aggregation
    1. Inflammatory reaction results in Coronary ArteryPlaque rupture resulting in Acute Coronary Syndrome
    2. Vasospasm may also be present
  • Findings
  1. Acute Coronary Syndrome onset within 1 hour of Allergic Reaction in 80% of cases
  • Types
  1. Type 1: Vasospasm only
  2. Type 2: Vasospasm AND coronary thrombosis
  3. Type 3: Vasospasm AND stent thrombosis
  • Management
  1. Manage as Acute Coronary Syndrome
  2. Manage Anaphylaxis
    1. Exercise caution with Anaphylaxis management that may provoke coronary disease (e.g. Epinephrine)
    2. Exercise caution with Acute Coronary Syndrome management that may provoke Allergic Reaction
      1. Beta Blockers may blunt Epinephrine response and Morphine (and other Opioids) may release Histamine
  • References
  1. Mattu and Demeester in Herbert (2021) EM:Rap 21(6): 3-4
  2. Kounis (1991) Br J Clin Pract 45:121-8 [PubMed]
  3. Memon (2015) Proc (Bayl Univ Med Cent) 28(3):358-62 [PubMed]