Key Points
- Simultaneously manage anaphylaxis and myocardial ischemia.
- Differentiate vasospasm (Type I) from plaque disruption (Type II).
- Coordinate cardiology–allergy care for culprit identification and secondary prevention.
Algorithm
- Primary survey and stabilization; focused history and exam.
- Order high‑yield tests first; escalate imaging as indicated.
- Initiate disease‑specific therapy and supportive care.
- Reassess clinical response; arrange consultation and disposition.
Clinical Synopsis & Reasoning
Chest pain and ST‑changes during anaphylaxis or hypersensitivity reaction suggests Kounis syndrome (allergic ACS). Mast‑cell activation causes coronary spasm or plaque rupture. Obtain ECGs and troponins; manage anaphylaxis while balancing ACS therapy risks (e.g., cautious use of beta‑blockers).
Treatment Strategy & Disposition
Treat anaphylaxis first (IM epinephrine, airway/oxygen, antihistamines, corticosteroids); for Type I (vasospastic) consider nitrates and calcium‑channel blockers. Apply ACS algorithms when plaque rupture is likely (DAPT, anticoagulation) with allergy and cardiology input.
Epidemiology / Risk Factors
- Epidemiology varies by setting; see citations for details.
Investigations
| Test | Role / Rationale | Typical Findings | Notes |
|---|---|---|---|
| ECG, serial troponins | Detect ischemia/injury | ST changes, ↑troponin | — |
| Allergy evaluation | Identify trigger | Culprit drug/food/insect | — |
| Coronary angiography (selected) | Define mechanism | Spasm vs plaque rupture | — |
Pharmacology
| Medication | Mechanism | Onset | Role in Therapy | Limitations |
|---|---|---|---|---|
| Epinephrine (IM) | α/β‑agonist | Minutes | First‑line anaphylaxis | Titrate; avoid unopposed α with β‑blockade |
| Nitroglycerin | Vasodilator | Minutes | Relieve vasospasm | Hypotension, headache |
| Aspirin | COX inhibitor | Minutes | ACS therapy when indicated | Allergy/bleeding |
Prognosis / Complications
- Prognosis depends on timeliness of diagnosis, comorbid disease, and response to therapy.
Patient Education / Counseling
- Explain expected course, warning signs requiring urgent care, and follow‑up testing.
- Review medication use, interactions, and monitoring parameters.