An allergy is a hypersensitive response by the natural immune system to exposure to certain foreign substances such as pet dander, mites, molds, foods, and even medications. The common allergy-producing substances are called allergens. The response to such substances is exaggerated in people allergic to those substances as compared with non-allergic people.
The immune system in non-allergic people takes these foreign substances as harmless and doesn’t cause a reaction to exposure to such substances. In allergic people, the immune system generates a response as if the foreign substance is harmful like a pathogen and tries to destroy it.
The immune system of an individual with allergy reacts to the allergen as if it’s a bacterium, virus or toxin. The immune system releases immunoglobulin E (IgE), an antibody, to destroy the allergen. The release of IgE, triggers the production of certain chemicals such as histamine in the body. These chemicals cause the allergic reactions that appear to be caused by the allergens. For example, histamine causes tightening of the muscles in the airways and makes the lining of the nose produce more mucus.
It is not the allergens that cause the allergies, it’s the immune system that takes the harmless allergens for harmful pathogens and generates and exaggerated response. Also the allergic reaction is not immediate. In fact the immune system takes time to remember the allergen. With time the immune system remembers the allergen and becomes sensitive to it. This process is called sensitization and may take from a few days to several years. Once the immune system is sensitive to an allergen, it generates antibodies to fight the allergen which lead to allergic sign and symptoms.
Common allergens that may cause allergic reactions in susceptible persons include dust mites, wool, animal dander, penicillin, egg white, fish, milk, peanuts, wheat, soy, mosquito stings, bee venom, horseflies, fleas, moths, household chemicals and more.
Allergies are usually diagnosed through questioning and certain tests. The doctor will ask certain questions allergy symptoms, the time and frequency of occurrence. The doctor may then recommend tests such as blood test to measures levels of IgE antibodies released by the immune system, or a skin prick test where the skin is pricked with small amount of a possible allergen to notice the reaction. The doctor may also recommend a Patch test for patients with eczema.
Anyone can develop an allergy to a possible allergen at any age. One can develop an allergy with age. It is also possible to outgrow an allergy over time. The most effective treatment and management of an allergy is to avoid exposure to the allergen. Medications can help with the symptoms of the allergies but do not cure the allergy itself.
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