Drug Allergies

Question 1

Type I Drug Allergy

Answer 1

Immunoglobulin E (IgE) mediated: anaphylaxis, hives, angioedema, bronchospasm

Question 2

Type II Drug Allergy

Answer 2

Cytotoxic on blood cells (anemia, thrombocytopenia)

Question 3

Type III Drug Allergy

Answer 3

Immune-complex = serum sickness, vasculitis, arthralgia

Question 4

Type IV Drug Allergy

Answer 4

Delayed hypersensitivity = skin rash, organ-tissue damage, contact sensitivity

Question 5

Penicillin allergy

Answer 5

True IgE reaction is rare, and decreases over time.

Less cross reactivity with carbapenems, no cross reactivity with aztreonam

Epstein-Barr virus + aminopenicillin = maculopapular rash. Not an allergy.

Question 6

Cephalosporin allergy

Answer 6

Rare - will appear as maculopapular rash or drug fever

Question 7

Cephalosporin and penicillin cross reactivity

Answer 7

-Highest chance with first generation cephalosporins, excluding cefazolin

-Cross reactivity depends on R1 side chain

Similar R1 amino chain: amoxicillin, ampicillin, cephalexin, cefadroxil, cefaclor

Similar R1 methoxyimino chain: cefuroxime, ceftazidime, ceftriaone, cefpodoxime, cefotaxime, cefepime

Question 8

Sulfa allergy

Answer 8

Often associated with SJS or TENS. Delayed onset.

Cross reactivity with other sulfonamides is not usually a concern, exception is sulfasalazine