Allergy is the exaggerated and out-of-place reaction of the immune system to external substances or stimuli that are not harmful to the body so the reaction actually damages the body instead of helping it. The hypersensitive response of the immune system of an allergic individual to a substance.

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These substances are known as allergens and are found in dust mites pets pollen insects ticks moulds foods and some medications.

Allergic reaction medical term definition. Allergic reactions are exaggerated sensitivities hypersensitive reactions that occur when your immune system responds abnormally to common substances such as pollen dust and certain foods. An anaphylactic reaction is a hypersensitivity type-I reaction which follows re-exposure to an antigen to which the body has previously formed an IgE antibody. Al-lerjik pertaining to or having an allergy.

An allergen is a substance that can cause an allergic reaction. Allergic reactions are sensitivities to substances called allergens that come into contact with the skin nose eyes respiratory tract and gastrointestinal tract. When the person is exposed to that allergen again an allergic reaction may.

A substance that triggers an allergic reaction in a person whos sensitive to it. Type I or anaphylactic reactions type II or cytotoxic reactions type III or immunocomplex reactions and type IV or cell-mediated reactions. Anaphylaxis is a severe whole-body allergic reaction to a chemical that has become an allergen.

Allergic Reaction A hypersensitivity reaction is an immunological reaction leading to tissue damage and was first described by Charles Richet in 1902. Read medical definition of Allergic reaction. A misguided reaction to foreign substances by the immune system the body system of defense against foreign invaders particularly pathogens the agents of infection.

An allergic reaction occurs when cells in the immune system interpret a foreign substance or allergen as harmful. The definition of allergy Allergy occurs when a person reacts to substances in the environment that are harmless to most people. An excessive reaction local or systemic or inappropriate immune response to an antigen.

This reaction can occur when the immune system attacks a normally harmless substance the allergen. Allergy is the exaggerated and out-of-place reaction of the immune system to external substances or stimuli that are not harmful to the body so the reaction actually damages the body instead of helping it. Four types of immune responses are usually described but the main reaction involving the eyes is type 1.

Within seconds of exposure to the antigens which may be proteins polysaccharides and haptens IgE molecules cross-link on the surface of mast cells and basophils stimulating vesicle degranulation and release of LBW mediators of anaphylaxis. When an allergen enters the body it causes the bodys immune system to develop an allergic reaction in a person with an allergy to it. Allergic reaction a local or general reaction characterized by altered reactivity of the animal body to an antigenic substance.

This reaction can occur when the immune system attacks a normally harmless substance the allergen. When an allergen enters the body it causes the bodys immune system to develop an allergic reaction in a person with an allergy to it. Allergists recognize four types of allergic reactions.

Type 1 hypersensitivity An immediate abnormal reaction occurring when an antigen reacts with an. The may be pollen and foods as well as insect stings drugs and almost any other substances. After being exposed to a substance such as bee sting venom the persons immune system becomes sensitized to it.

They are also called allergic reactions types 1-4. ă-lĕrjik rē-akshŭn A local or general reaction of an organism following contact with a specific allergen to which it has been previously exposed and sensitized. The hypersensitive response of the immune system of an allergic individual to a substance.

A doctor who diagnoses and treats allergy-related conditions. The allergic reaction is misguided in that these foreign substances are usually harmless. Medical Dictionary for the Health Professions and Nursing Farlex 2012.

Foot and Ankle Injection Techniques 2010. They can be breathed into the lungs swallowed or injected.