Term
Hypersensitivity or Allergy |
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Definition
An increased or excessive response to the presence of an antigen to which the patient has been previously exposed. |
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Term
Type 1: Immediate or Atopic Allergy |
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Definition
-Most common type. -EX: Anaphylaxis and Allergic Asthma, latex |
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Term
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Definition
Causes widespread blood vessel dilation leading to decreased CO and bronchoconstriction. |
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Term
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Definition
-Body makes special autoantibodies directed against self cells that have some form of foreign protein attached to them. Destroying both cells. -EX: Hemolytic anemia, thrombocytopenic purpura, hemolytic trasfusion reactions (receipt of wrong blood type), Good pastures syndrome and drug induced hemolytic anemia. -TX: discontinue product, followed by symptomatic treatment. |
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Term
Type III: Immune Complex Reactions |
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Definition
-Excess antigens cause immune complexes to form in the blood. They then lodge in small blood vessels walls which triggers inflammation and tissue or vessel damage results. -EX: Common locations kidneys, joints and skin. RA, SLE -Serum sickness caused by penicillin and other drugs. |
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Term
Type IV: Delayed Hypersensitivity Reactions. |
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Definition
-Antibodies and complement are not involved. -Sensitized T-cell from previous exposures respond to an antigen by releasing chemical mediators and triggering macrophages to destroy the antigen. -reaction Occurs hours to days later, and its local. -EX: PPD, contact dermatitis, poison ivy, insect stings, tissue transplant rejection and sarcoidosis. |
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Term
Type V: stimulatory reaction |
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Definition
-caused by excessive stimulation of a normal cell surface receptor by an autoantibody, resulting in a continuous "turned-on" state of the cell. -EX: Graves or hyperthyroidism -goal is to remove the cause of over secretion or stimulation. |
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