Difference between revisions of "Hypersensitivity reaction"

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(Clinical Features)
 
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#REDIRECT[[Acute allergic reaction]]
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==Background==
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*Uncomfortable, damaging, and sometimes fatal reactions produced by the normal immune system including allergies and autoimmunity.
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==Clinical Features==
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{| class="wikitable"
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|-
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! Type !! Mechanism !! Example
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|-
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| I: Allergy, Immediate || IgE-mediated degranulation of mast cells and basophils; usually happens after a first exposure which causes sensitization || [[Urticaria]], [[anaphylaxis]], [[angioedema]]
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|-
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| II: Cytotoxic, Antibody Dependant || IgG or IgM antibodies react with cell antigens with resultant complement activation || [[Myasthenia gravis]], [[goodpasture syndrome]], erythroblastalis fetalis, AI hemolytic anemia, Graves disease
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|-
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| III: Immune Complex || IgG immune complex deposition and subsequent complement activation || [[Serum sickness]], RA, [[SLE]], [[poststreptococcal glomerulonephritis]]
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|-
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| IV: Cell-mediated, Delayed || Activated T cells against cell surface antigens || TB skin test, chronic transplant rejection, delayed drug rashes, [[contact dermatitis]]
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|}
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==See Also==
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*[[Acute allergic reaction]]
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==References==
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<references/>
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[[Category:Dermatology]] [[Category:Rheumatology]]

Latest revision as of 02:58, 2 March 2020

Background

  • Uncomfortable, damaging, and sometimes fatal reactions produced by the normal immune system including allergies and autoimmunity.

Clinical Features

Type Mechanism Example
I: Allergy, Immediate IgE-mediated degranulation of mast cells and basophils; usually happens after a first exposure which causes sensitization Urticaria, anaphylaxis, angioedema
II: Cytotoxic, Antibody Dependant IgG or IgM antibodies react with cell antigens with resultant complement activation Myasthenia gravis, goodpasture syndrome, erythroblastalis fetalis, AI hemolytic anemia, Graves disease
III: Immune Complex IgG immune complex deposition and subsequent complement activation Serum sickness, RA, SLE, poststreptococcal glomerulonephritis
IV: Cell-mediated, Delayed Activated T cells against cell surface antigens TB skin test, chronic transplant rejection, delayed drug rashes, contact dermatitis

See Also

References