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30 Cards in this Set
- Front
- Back
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what is the property of type 1 reactions
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upon initial exposure b/t cells make IgE
IgE is then found on the surface of mast cells upon 2nd exposure to the drug cross linking w/ IgE on mast cells cause release of inflammatory mediators |
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is type 1 reaction dose dependent or independent
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dose dependent
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what are the clinical features of type 1
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skin
respiratory compromise hypotension (reduced BP) N/V/D |
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what are the diagnostic criteria for anaphylaxis
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acute onset with involvement of skin mucosa + respiratory compromise or reduced BP
two or more of the following occur rapidly after exposure to antigen -reduced BP -respiratory compromsise -persistent GI symptoms -involvement of skin mucosal tissue reduced BP after exposure (SBP < 90 or 30% or greater decrease from baseline) |
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normally IgE mediated reactions do not begin several days into therapy under what circumstance could they
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pt skips a dose and restarts after initial exposure
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when pt has anaphylaxis what is done for immediate exposure
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IM epinephrine
fluid resuscitation supplemental O2 place pt supine or semi-recumbent position |
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if pt is not responsive to IM epi and fluid resuscitation what can be done?
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IV epinephrine b/c they may not be properly perfusing their muscle therefore no drug is reaching the blood stream
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what are the adjunctive therapies aside from epi for management of anaphylaxis
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glucagon - inotropic/chronotropic effects
antihistamines - releive itching/pruritis and mediator release, has no affect on airway restrictions, GI symptoms, or shock bronchodilators (ex: albuterol nebulizer) - relieve bronchospasm but does nothing to relieve mucosal edema in upper airway glucocorticoids - limited to preventing bisphasic anaphylaxis |
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what are common pseudoallergic reactions
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red man/red neck syndrome with vancomycin
opiates amphotericin B aspirin |
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what occurs in type 2 reaction
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involves antibody mediated cell destruction
drug binds to platelet complex seen as foreign material antibody destroys complex |
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what disease are typical presentations of type 2 reaction
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thrombocytopenia
hemolytic anemia agranulocytosis |
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what are the symptoms in thrombocytopenia, hemolytic anemia, agranulocytosis
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hemolytic anemia - dyspnea, fatigue, jaundice, bounding pulse
thrombocytopenia - petechia in skin/oral mucosa, spenomegaly, hepatomegaly agranulocytosis - fever, stomatitis, pharyngitis, pneumonia, sepsis |
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what occurs in type 3 reactions
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caused by antigen antibody complex
drug binds to drug specefic IgG antibody forming an immune complex immune complex binds to FcR + activates compliment compliment activation leads to inflammatory mediator release leads to inflammation |
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what are the clinical presentation of type 3 reactions
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serum sickness
vasculitis drug fever |
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what is used in treatment of type 3 reactions
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antihistamine for pruritis/rash
NSAID for arthralgia corticosteroids for extensive disease |
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what occurs in type 4 reactions
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mediated by T cells NOT ANTIBODIES
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what are the various types of Type 4 reactions and what is activated in each
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type 4A - activates TH1 macrophage
type 4B - activates TH2 eosinophils type 4C - activates CTL type 4D - activates neutrophils |
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what are type 4 reactions primarily seen as
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contact dermatitis
morbilliform eruptions (maculopapular) |
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what is SJS and TEN in relation to %BSA
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SJS < 10%
TEN > 30% |
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what is SJS/TEN characterized by
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target and bullous lesions leading to necrosis and sloughing of epidermis
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what is the adjunctive therapy for management of SJS/TEN
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glucocorticoids
IV immunoglobulins |
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anaphylaxis involves what organ systems
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multiple lol
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what type of reaction is the PCN skin test predictive for
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type 1 IgE mediated
-90% of pts with PCN allergy test negative |
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what is the likely hood of reaction occuring if pt has positive skin test
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if pt test positive they have 50% chance of reaction occuring upon rechallenge
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PCN have increase likely hood of cross re-activity with what B lactam
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1st generation cephalosporins due to their R group
no cross reactivity with aztreonam |
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what are the properties of desensitization
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gives temporary tolerence
makes mast cells less responsive to degranulation pt receive UNINTERRUPTED course of medication |
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what type of reaction can desensitization be used
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type 1 IgE mediated reaction
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what pts can not get desensitization
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history of PCN induced SJS/TEN
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what are sulfonamide hypersensitivity usually do
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T cell mediated mechanism (type 4 reaction)
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what is more likely to cause SJS/TEN PCN or Sulfonamide hypersensitivity
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sulfonamide
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