Unusual Heart Attack Triggered by COVID-Linked Allergic Skin Rash Alarms Doctors in China!

Medical News: A surprising and rare medical case from China is shedding new light on how COVID-19 may spark unexpected and dangerous heart complications - even in people without major blockages in their heart arteries. Doctors at the Affiliated Hospital of Jining Medical University have detailed an unusual case involving a 58-year-old woman who developed a severe allergic skin reaction following a COVID-19 infection. Shockingly, this led to a type of heart attack known as Kounis syndrome - a condition triggered by an allergic reaction that causes the coronary arteries to spasm and restrict blood flow to the heart.

Kounis syndrome. Current classification in 3 subtypes based on allergic pathogenic mechanisms and ensuing effects. Type 1 usually occurs in normal or near-normal coronary arteries, largely due to histamine degranulation from mast cells, catecholamine storm, endothelin release, and other cytokines (MINOCA syndrome). Type 2 is usually seen in patients with quiescent pre-existing coronary artery disease (CAD) and may result in acute coronary syndrome/myocardial infarction. Type 3 affects patients with coronary artery stenting, with subsequent acute thrombosis or restenosis.

The woman initially sought help for what seemed to be a straightforward allergic skin reaction - itchy red welts and rashes known as urticaria. She had a high fever, chills, and abdominal discomfort. A routine test for COVID-19 came back negative. Doctors treated her with anti-allergy medications and antibiotics, but her symptoms persisted. Over the following days, she developed additional signs of illness, including frequent urination, cough, and eventually, chest pain. This Medical News report traces how what began as an apparent skin allergy turned into a full-blown cardiovascular emergency.
 
A Chain Reaction of Symptoms
Despite no previous allergies or family history of heart disease, the patient began experiencing increasingly severe symptoms. After a few days, a repeat COVID-19 test returned positive. Soon after, she suffered a severe chest pain episode accompanied by changes in her electrocardiogram (ECG) indicating an acute heart event.
 
Troponin levels - a protein released during heart muscle injury - were elevated, confirming damage to her heart. However, when doctors performed coronary angiography to check for blocked arteries, the results were puzzling. Her arteries had only mild stenosis (narrowing) and no major blockages. This pattern did not match that of a classic heart attack caused by a clogged artery.
 
Doctors instead diagnosed her with Type II Kounis syndrome, a rare and often underdiagnosed condition in which allergic reactions cause inflammation and spasms in the heart’s blood vessels, leading to symptoms of a heart attack.
 
What Is Kounis Syndrome and Why Is It Dangerous
Kounis syndrome, also known as “allergic myocardial infarction,” was first described in the 1990s. It occurs when inflammatory chemicals released during an allergic reaction cause spasms in the coronary arteries or worsen pre-existing plaques, leading to re duced blood flow and chest pain or even full-blown heart attacks.
 
The condition is categorized into four types:
-Type I affects individuals with no pre-existing coronary disease, causing spasms through allergy alone.
 
-Type II occurs in people with underlying coronary artery disease, where allergic inflammation can trigger a more dangerous episode by disrupting plaques.
 
-Type III involves thrombosis of coronary stents.
 
-Type IV applies to those with previous coronary artery bypass grafts.
In this case, the woman’s Type II diagnosis means she likely had some underlying arterial changes made worse by the allergic response to COVID-19.
 
The Domino Effect of COVID-19 on the Body
COVID-19 has long been known to affect the lungs and immune system, but newer evidence shows it can also lead to unexpected complications in the skin and heart. Studies suggest that the virus may activate mast cells - immune cells that release histamines and other inflammatory mediators. These compounds can cause both skin reactions like urticaria and trigger spasms in heart vessels.
 
The patient had high levels of immunoglobulin E (IgE) - an allergy marker - and inflammatory proteins such as C-reactive protein (CRP) and serum amyloid A. These lab results confirmed that her body was mounting a strong allergic and inflammatory response, likely provoked by the COVID-19 virus.
 
The chest pain episodes kept recurring even after the initial treatment. Doctors had to adjust her medications multiple times, including giving her antiplatelet drugs (aspirin and clopidogrel), vasodilators like nicorandil and diltiazem, corticosteroids such as methylprednisolone and prednisone, and antiviral therapy with simnotrelvir and ritonavir.
 
Eventually, after more than two weeks of intensive care, her condition improved. Her rashes cleared, repeat heart tests showed no lasting damage, and she was discharged. At a one-month follow-up, there were no signs of recurrent angina or urticaria.
 
Key Lessons and New Warning Signs
This case highlights the need for doctors to consider allergic reactions and COVID-19 as potential contributors to heart symptoms. Even in patients without a history of heart disease or with normal coronary scans, allergic reactions could be dangerous, especially when triggered by viral infections like SARS-CoV-2.
 
Most people wouldn’t associate a skin rash with a heart attack, but as this case shows, symptoms can cascade unpredictably. Kounis syndrome remains underrecognized, and awareness among healthcare professionals and the public is crucial.
 
Early warning signs may include:
-Sudden rashes or hives, especially after an infection
-Chest pain without typical risk factors
-Elevated allergy and inflammatory markers (like IgE or CRP)
-ECG changes and mild troponin increases without significant artery blockages
 
Conclusion
This unique case involving a Chinese woman with post-COVID urticaria and recurrent chest pain underscores the complex interplay between viral infections, allergic reactions, and cardiovascular health. It also reveals how COVID-19 can act as a hidden trigger for Kounis syndrome, an underdiagnosed cause of heart attacks that may be mistaken for traditional coronary artery disease.
 
Clinicians must remain vigilant when treating patients who present with overlapping symptoms such as rashes, allergic reactions, and heart pain. Dynamic ECG monitoring, biomarker testing, and careful patient history evaluation are key to identifying and managing such complex cases. More research is urgently needed to understand the exact mechanisms by which COVID-19 and other viral infections can provoke severe allergic and cardiovascular events. Recognizing such patterns early could save lives and prevent long-term complications in future patients.
 
The study findings were published in the peer reviewed journal: Frontiers in Cardiovascular Medicine.
https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2025.1542223/full
 
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