Dermatitis – Definition, Symptoms, Causes, Treatment

Definition of Dermatitis The different types of dermatitis are classified according to the cause of the condition. Contact dermatitis is the condition caused by an allergen or an irritating substance. Irritant contact dermatitis accounts for 80% of all cases of contact dermatitis. Atopic dermatitis is very common worldwide and increasing in prevalence. It affects males […]

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Allergen – what is, definition and Common Allergens

What is Allergen and definition A harmless substance, also called a hapten, that causes an exaggerated response from the IMMUNE SYSTEM called a HYPERSENSITIVITY REACTION. For reasons researchers do not fully understand, the immune system produces antibodies for the substance that result in the IMMUNE RESPONSE perceiving the substance as a foreign invader. When the allergen contacts or enters the body, […]

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Allergic asthma treatment and symptoms

What is Allergic Asthma and definition A HYPERSENSITIVITY REACTION (allergic reaction) that involves the airways (bronchi). allergic ASTHMA is a type I or IMMUNOGLOBULIN E (IgE) reaction. Mast cells in the bronchial membranes release HISTAMINE, PROSTAGLANDINS, and LEUKOTRIENES. These substances cause itching and swelling of the bronchial membranes, resulting in wheezing and the sensation of chest tightness. Cockroach droppings are the most frequent cause of […]

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Allergic conjunctivitis symptoms and treatment

Allergic conjunctivitis Definition and Symptoms Allergic conjunctivitis – A type I (IMMUNOGLOBULIN E [IgE]) HYPERSENSITIVITY REACTION, commonly called an allergic reaction, that affects the membranes that line the inner eyelids (conjunctiva). Sometimes the irritation also reddens the white part of the eye (sclera). Allergic CONJUNCTIVITIS features red and swollen conjunctiva with excessive tearing and itching of the eyes […]

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Allergic dermatitis symptoms and treatment

Allergic Dermatitis Definition Allergic dermatitis is a HYPERSENSITIVITY REACTION (allergic reaction) that affects the SKIN, usually in response to contact with an ALLERGEN. As with all hypersensitivity reactions, the first exposure to the allergen produces no symptoms. In reaction to the exposure, however, the IMMUNE SYSTEM produces antibodies for the allergen. Subsequent exposures to the allergen then do produce symptoms. […]

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Allergic Rhinitis – symptoms and treatment

What is Allergic Rhinitis and Definition Allergic Rhinitis is a HYPERSENSITIVITY REACTION to inhaled allergens – also called seasonal rhinitis or hay FEVER, affects the mucous membranes inside the NOSE (nasal mucosa). Allergic rhinitis affects about 40 million adults in the United States, making it one of the most common hypersensitivity reactions. The condition tends to develop in […]

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Allergy definition and symptoms

Allergy definition Allergy is an abnormal sensitivity to an ordinarily harmless substance, called an ALLERGEN, that produces a HYPERSENSITIVITY REACTION (allergic reaction) in response to the IMMUNE SYSTEM’s detection of the substance’s presence. A person can have an allergy to nearly any substance. Though researchers understand the mechanisms of hypersensitivity reaction, they do not know what causes the immune system to […]

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Allergy testing

Allergy Testing Definition and Information Allergy Testing is a diagnostic procedures to determine the allergens responsible for HYPERSENSITIVITY REACTION. The most specific ALLERGY test is the allergy SKIN test, also called a scratch test or a patch test. For this test, the allergist uses the inside of the arm or a section of the back to expose the […]

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Anaphylaxis – definition, symptoms and treatment

What is Anaphylaxis and definition Anaphylaxis is a severe HYPERSENSITIVITY REACTION (allergic reaction) in which the tissues of the throat swell, preventing air from getting to the LUNGS. Anaphylaxis, also called anaphylactic shock, is a type I hypersensitivity reaction that often develops rapidly, within minutes to an hour of exposure to the ALLERGEN. Hives, ANGIOEDEMA, and airway spasms are […]

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Angioedema – definition, causes, symptoms and treatment

What is Angioedema and Definition A HYPERSENSITIVITY REACTION (allergic reaction) that produces swelling and fluid accumulation beneath the surface of the SKIN, similar in appearance to URTICARIA (hives). Occurs in response to HISTAMINE release and typically affects the face, especially around the eyes and lips, and can be life threatening when it is severe or if it develops in the throat. […]

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