Allergies - Symptoms and causes - Mayo Clinic
2024年8月24日 · Overview. Allergies happen when the immune system reacts to a foreign substance that gets inside the body. These substances are known as allergens. They include pollen, bee venom and pet dander. Allergies also can happen due to certain foods and medicines that don't cause reactions in most people.
Peanut allergy - Symptoms and causes - Mayo Clinic
2024年8月20日 · Peanut allergy is a condition that causes the body's germ-fighting immune system to react to peanuts. It's one of the most common causes of a life-threatening allergic reaction to food. This life-threatening reaction is known as anaphylaxis.
Allergies and asthma: They often occur together - Mayo Clinic
2021年5月14日 · In some people, skin or food allergies can cause asthma symptoms. This is called allergic asthma or allergy-induced asthma. James T C Li, M.D., Ph.D., a Mayo Clinic allergy specialist, answers questions about the link between allergies and asthma.
Food allergy - Symptoms and causes - Mayo Clinic
2024年8月30日 · Causes. When you have a food allergy, your immune system mistakenly identifies a specific food or a substance in food as something harmful. In response, your immune system triggers cells to make an antibody known as immunoglobulin E (IgE) to recognize the allergy-causing food or food substance, called an allergen.
Latex allergy - Symptoms and causes - Mayo Clinic
2024年11月6日 · Latex allergy may cause itchy skin and hives or even anaphylaxis, a potentially life-threatening condition that can cause throat swelling and severe difficulty breathing. Your health care provider can determine if you have a latex allergy or if …
Hay fever - Symptoms and causes - Mayo Clinic
2024年8月13日 · Hay fever, also called allergic rhinitis, causes cold-like symptoms. These may include a runny nose, itchy eyes, congestion, sneezing and sinus pressure. But unlike a cold, hay fever isn't caused by a virus.
Anaphylaxis - Symptoms & causes - Mayo Clinic
2021年10月2日 · Anaphylaxis is a severe, life-threatening allergic reaction. It can happen seconds or minutes after you’ve been exposed to something you’re allergic to. Peanuts or bee stings are examples. In anaphylaxis, the immune system releases a flood of chemicals that can cause the body to go into shock.
Drug allergy - Symptoms and causes - Mayo Clinic
2024年11月9日 · Causes. A drug allergy happens when the immune system mistakenly identifies a medicine as a harmful substance, such as a virus or bacterium. Once the immune system detects a medicine as a harmful substance, it develops an antibody specific to that medicine.
Asthma - Symptoms and causes - Mayo Clinic
2024年4月6日 · Identify and avoid asthma triggers. A number of outdoor allergens and irritants — ranging from pollen and mold to cold air and air pollution — can trigger asthma attacks. Find out what causes or worsens your asthma, and take steps to …
Contact dermatitis - Symptoms and causes - Mayo Clinic
2024年5月2日 · Contact dermatitis is an itchy rash caused by direct contact with a substance or an allergic reaction to it. The rash isn't contagious, but it can be very uncomfortable. Many substances can cause this reaction, such as cosmetics, fragrances, jewelry and plants.