Hypersensitivity reaction: Difference between revisions
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==Background== | |||
*Uncomfortable, damaging, and sometimes fatal reactions produced by the normal immune system including allergies and autoimmunity. | |||
==Clinical Features== | |||
{| class="wikitable" | |||
|- | |||
! 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, post-strep glomerularnephritis | |||
|- | |||
| IV: Cell-mediated, Delayed || Activated T cells against cell surface antigens || TB skin test, chronic transplant rejection, contact dermatitis | |||
|} | |||
==See Also== | |||
*[[Acute allergic reaction]] | |||
*[[Anaphylaxis]] | |||
*[[Angioedema]] | |||
*[[Lupus]] | |||
*[[Serum Sickness]] | |||
*[[Contact dermatitis]] | |||
==References== | |||
<references/> | |||
Revision as of 01:22, 21 October 2015
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, post-strep glomerularnephritis |
| IV: Cell-mediated, Delayed | Activated T cells against cell surface antigens | TB skin test, chronic transplant rejection, contact dermatitis |