Since mid-August, the difficult “allergy” season for many people has come again. From August to near October, many people suffer from “allergic rhinitis”, “allergic asthma” and other diseases that are particularly severe due to “pollen” or other plant-related allergies. Some people also experience rashes and itching, along with heartburn and an irregular pulse on their own. Is this arrhythmia related to allergies? The answer is yes. When an allergic reaction occurs in the body, it not only affects the skin, digestive and respiratory systems, causing rashes, diarrhea and asthma, but also the heart, highlighted by arrhythmias. Doctors call these arrhythmias allergic arrhythmias. Allergic arrhythmias are not uncommon, but they are easily overlooked. This is because people rarely associate allergy symptoms with heart disease. If the symptoms of arrhythmia are severe and the patient has palpitations, premature beats, tachycardia and significant abnormalities in the electrocardiogram, people will consider that they may have some kind of heart disease, or just consider the simple arrhythmia and rarely consider its relationship with allergic reactions. Cardiac allergy is due to the occurrence of urticaria (commonly known as “rubella”) on the skin, the body produces a metabolic reaction, causing the heart’s coronary arteries to constrict and reduce blood flow, coupled with varying degrees of expansion of the heart’s capillaries and small veins, increased permeability, and cellular leakage in the plasma, resulting in uneven inflammatory edema in the interstitial space of the heart. At this point, the focus of the patient’s discomfort is no longer on the itchy skin papules, but on chest tightness and distress, shortness of breath, panic and irritability, and even critical manifestations similar to myocardial infarction due to angina pectoris. Therefore, when a patient develops urticaria followed by cardiac symptoms, the possibility of cardiac allergy should be considered and anti-allergic treatment should be given promptly. Antihistamines are selected according to the condition, and the application of antiarrhythmic drugs, such as glucocorticoids, diphenhydramine, and scopolamine, can be considered if necessary. Those with fast heart rate may be treated with additional drugs such as benadryl and valium, while those with moderate to severe atrioventricular block may be treated with atropine. Generally speaking, the prognosis for allergic arrhythmias is good, as the allergic symptoms subside the arrhythmia will gradually resolve or disappear, leaving few sequelae. The severity of the allergic reaction is directly proportional to its effect on the heart, and the occurrence of allergy in elderly people who are already suffering from cardiovascular disease is tantamount to “adding insult to injury”, which is even more dangerous and can be life-threatening in serious cases. To our friends: If you have severe seasonal allergy symptoms, especially allergic rhinitis, hives and other symptoms, try to avoid lifting with allergens, wear a mask when traveling, try to wear long-sleeved clothes, and apply air purifiers indoors.