Hypersensitivity Reactions Flashcards
Players in Type 1
IgE, plasma and mast cells
Drugs associated with allergic reactions
beta lactams
aspirin and NSAIDs (asthmatics)
sulfonamides
anaphylaxis
life threatening - fatality greatest in first few hours
respiratory depression
laryngeal edema
hypotension
observation up to 12 hours in ER due to late phase reactions
Type 1 treatment
epinephrine 1:1000 (0.3mg) IM Oxygen if needed 25-50mg parental diphenhydramine H2R blocker for late phase IV fluids for hypotension nebulized albuterol if no Epi progress
Penicillins and Cephalosporins cross reactivity
5-15% side chain moiety skin testing is unreliable avoid carbapenems Aztreonam OK
Erythroblastosis fetalis
leakage of Rh0 D positive RBC from fetus into mother’s circulation results in sensitization with anti-Rh0 D antibodies forming
Rho-Gam
Rh0D-IG suppresses AB response and formation of anti-Rh0 D ABs after fetal exposure
72 hours term pregancy and 28 weeks in
Type 3
AB-AG complexes deposit resulting in tissue damage due to complement
exogenous AG
gluten allergy and serum sickness
endogenous AG
drug-induced lupus
serum sickness sx
flu-like, 5 to 10 days after AG exposure
arthus reaction
localized to an organ
serum sickness treatment
removal of the AG - corticosteroids
contact dermatitis treatment
topical steroids
antihistamine
topical immunomodulators
systemic steroids
PPD test
type 4a
in previously exposed people-wheal+flare = positive
