what is allergy?
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allergy allergy. n, pl-gies. 1. (Pathology) a hypersensitivity to a substance that causes the body to react to any contact with that substance. Hay fever is an allergic reaction to pollen. 2. aversion: he has an allergy to studying.
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Allergies An allergy occurs when your body’s immune system sees a certain substance as harmful. It reacts by causing an allergic reaction. Substances that cause allergic reactions are allergens. There are many types of allergies. Some allergies are seasonal and others are year-round. Some allergies may be life-long. It is important to work with your health care provider to create a plan to manage your allergy.
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Top 30 Doctor insights on: Tb Test Allergic Reaction Symptoms Allergic Reaction (Definition) Allergic reactions are sensitivities to substances, called allergens, that come into contact with the skin, nose, eyes, respiratory tract, and gastrointestinal tract. They can be inhaled into the lungs, swallowed, or injected.
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- Allergies occur when your immune system reacts to a foreign substance — such as pollen, bee venom or pet dander — that doesn't cause a reaction in most people. Your immune system produces substances known as antibodies. Some antibodies protect you from unwanted invaders that could make you sick or cause infection.
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Allergies Allergies occur when your immune system reacts to a foreign substance — such as pollen, bee venom or pet dander — or to a food that doesn't cause a reaction in most people. Your immune system produces substances known as antibodies.
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Patch testing for skin allergies An allergic reaction is specific to the individual and to a substance (or a group of related substances) called an allergen. Allergy is a hypersensitivity (oversensitivity) to a particular substance, and always involves the immune system. All areas of skin that are in contact with the allergen develop the rash.
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- Allergy Facts. Asthma and allergic diseases, such as allergic rhinitis (hay fever), food allergy, and eczema, are common for all age groups in the United States. Asthma affects more than 24 million people in the U.S., including more than 6 million children. 1
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- An allergy occurs when you react to things like pollen and cats that don’t affect most people. If you come into contact with something you are allergic to (called an allergen), you may have symptoms. This is called an allergic reaction. Asthma is a lung disease that makes it hard to breathe at times.
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Food allergies in children Food allergies in children What is a food allergy? A food allergy is an abnormal response of the body to a certain food. It is important to know that this is different than a food intolerance, which does not affect the immune system, although some of the same symptoms may be present. What causes food allergies?
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Allergies in toddlers An allergy is an immune reaction to a substance in the environment called an allergen. How to allergy-proof your home Learn easy steps for reducing dust, pet dander, and other allergens at home. How to allergy-proof your home.
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Allergy Facts Allergy Facts Asthma and allergic diseases, such as allergic rhinitis (hay fever), food allergy, and eczema, are common for all age groups in the United States. Asthma affects more than 17 million adults and more than 7 million children.1.
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Allergies What Are the Symptoms of an Allergy? An allergy occurs when the body’s immune system sees a substance as harmful and overreacts to it. The symptoms that result are an allergic reaction. The substances that cause allergic reactions are allergens. Allergens can get into your body many ways to cause an allergic reaction. 1  You can inhale allergens into your nose and your lungs. 2  You can ingest allergens by mouth. 3  Your body can have allergens injected into it.  Your skin can absorb allergens.
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- 1 Allergies are reactions of your immune system to one or more things in the environment.  The immune system is your body's defense system. In allergic reactions, however, it is responding to a false alarm.
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Allergies and Allergic Reactions Allergies and Allergic Reactions. Allergies and allergic reactions can affect your immune system. By: Stewart Hare. Allergies are disorders of the immune system, which when a foreign substance that is normally harmless in most people causes an extreme reaction within the body.
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- allergen-any substance that can cause an allergy. substance-a particular kind or species of matter with uniform properties; shigella is one of the most toxic substances known to man.ragweed pollen-pollen of the ragweed plant is a common allergen. Translations.. A substance, such as pollen, that causes an allergy. [German. : , allergy; see allergy +. , -gen (from French. ; see-gen).]. al′ler·gen′ic (-jĕn′ĭk) adj.
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Allergy Shots Allergies are the result of a chain reaction that starts in the immune system. Your immune system controls how your body defends itself. For instance, if you have an allergy to pollen, your immune system identifies pollen as an invader or allergen.
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Allergen An allergen is a type of antigen that produces an abnormally vigorous immune response in which the immune system fights off a perceived threat that would otherwise be harmless to the body.
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Allergy (Allergies) Allergy overview. This is a review regarding how the allergic response of the immune system occurs and why certain people become allergic. The most common allergic diseases are described, including allergic rhinitis (nasal allergies), allergic conjunctivitis (eye allergies), allergic asthma, urticaria (hives), and food allergies.
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allergen allergen. 1. a substance, protein or nonprotein, capable of inducing allergy or specific hypersensitivity. 2. a purified protein of a food (such as milk, eggs, or wheat), bacterium, or pollen. adj., adj allergen´ic. Allergens are used to test a patient for hypersensitivity to specific substances (see skin test).. an extract of any substance known to cause allergy. Allergens are used to test a patient for hypersensitivity to specific substances (see skin test). They are also used to densensitize or hyposensitize allergic individuals. See immunotherapy. Almost any substance in the environment can be an allergen.
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Allergies Anaphylaxis (anna-fih-LACK-sis) is a severe allergic reaction that can be life-threatening and requires immediate medical attention. It happens fast and may cause death. Symptoms usually involve more than one part of the body, such as the skin or mouth, the lungs, the heart and the gut. Learn more about anaphylaxis.
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Allergy Allergies, also known as allergic diseases, are a number of conditions caused by hypersensitivity of the immune system to something in the environment that usually causes little or no problem in most people. These diseases include hay fever, food allergies, atopic dermatitis, allergic asthma, and anaphylaxis. Symptoms may include red eyes, an itchy rash, runny nose, shortness of breath, or swelling. Food intolerances and food poisoning are separate conditions.
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Overview A drug allergy is the abnormal reaction of your immune system to a medication. Any medication — over-the-counter, prescription or herbal — is capable of inducing a drug allergy. However, a drug allergy is more likely with certain medications. The most common signs and symptoms of drug allergy are hives, rash or fever. A drug allergy may cause serious reactions, including anaphylaxis, a life-threatening condition that affects multiple body systems.
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- 1 Allergy involves an exaggerated response of the immune system, often to common substances such as foods or pollen.  The immune system is a complex system that normally defends the body against foreign invaders, such as bacteria and viruses, while also surveying for abnormal tissue changes, such as cancer.
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Top 30 Doctor insights on: Duration Of Allergic Reactions Allergies (Definition) Allergies occur when your immune system is triggered by envirionmental factors it should ignore--for example, pollen in the air, or dander on a cat or dog--and creates cells to fight against them. An allergic reaction typically causes itching, congestion, or drainage, and can be very serious. ...Read more.
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Medical Definition of Anergy Medical Definition of Anergy Anergy: A state of immune unresponsiveness. Induced when the T cell's antigen receptor is stimulated, effectively freezing T cell responses pending a second signal from the antigen-presenting cell. The delivery of the second signal by the antigen-presenting cell rescues the activated T cell from anergy, allowing it to produce the lymphokines necessary for the growth of additional T cells. T cells are small white blood cells that orchestrate and directly participate in the immune defenses.
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Overview Food allergy is an immune system reaction that occurs soon after eating a certain food. Even a tiny amount of the allergy-causing food can trigger signs and symptoms such as digestive problems, hives or swollen airways.t's easy to confuse a food allergy with a much more common reaction known as food intolerance. While bothersome, food intolerance is a less serious condition that does not involve the immune system.