Allergic Reactions Can Lead to Arrhythmias

As mid-August arrives, many people begin to experience the challenging allergy season. From August to nearly October, numerous individuals suffer from severe allergic rhinitis, asthma, and other allergic conditions due to pollen or plant-related allergens. Some also develop rashes, itching, and even feel palpitations with irregular pulse rates. But is there a connection between such arrhythmias and allergic reactions? The answer is yes.

How Allergies Impact Heart Rhythm

When the body experiences an allergic reaction, it doesn't just affect the skin, digestive system, or respiratory tract with symptoms like rashes, diarrhea, or asthma—it can also impact the heart. This phenomenon is known as allergic arrhythmia. Although it's not uncommon, it's often overlooked because people rarely associate allergic symptoms with heart conditions. When arrhythmias become severe, symptoms such as palpitations, premature beats, tachycardia, or significant ECG abnormalities may lead individuals to suspect a heart disease rather than an allergic reaction.

Understanding Cardiac Allergy

Cardiac allergy occurs when the body undergoes a hypersensitivity reaction, such as during urticaria (commonly known as hives), leading to coronary artery constriction and reduced blood flow. Additionally, capillaries and small veins in the heart may dilate to varying degrees, increasing permeability and causing plasma cells to leak into the cardiac interstitium. This results in uneven inflammatory edema in the heart tissue. At this stage, the patient's discomfort shifts from skin irritation to chest tightness, shortness of breath, coughing, and anxiety. In severe cases, symptoms can mimic those of a heart attack.

Recognizing Symptoms and Treatment Options

If a patient experiences cardiac symptoms after developing hives, cardiac allergy should be considered, and timely anti-allergy treatment administered. Treatment options may include antihistamines, and in some cases, anti-arrhythmic medications like corticosteroids, diphenhydramine, or anisodamine. For patients with tachycardia, propranolol and diazepam may be added, while atropine could be considered for moderate to severe atrioventricular block. Generally, the prognosis for allergic arrhythmias is favorable, with symptoms subsiding as the allergic reaction resolves, rarely leaving lasting effects.

Increased Risk for Those with Preexisting Conditions

The severity of an allergic reaction correlates with its impact on the heart. Older adults with preexisting cardiovascular conditions are particularly vulnerable—experiencing an allergic reaction can be like "adding insult to injury," potentially leading to life-threatening situations. Therefore, it's crucial for individuals with severe seasonal allergies, especially those involving allergic rhinitis or urticaria, to avoid allergens, wear masks when outdoors, cover skin with long sleeves, and use air purifiers indoors.