Drug Allergies

Question 1

Can a patient who develops SJS/TEN ever take the causal drug again?

Answer 1

No

Question 2

Cross-sensitivity of cephalosporins

Answer 2

10-20% when the patient is allergic to penicillin as well

Question 3

Qualifications of a Drug Allergy

Answer 3

The reaction is not a normal AE of the medication (ex: itching expected wth morphine but not PCN)
The reaction is immune related
Normal symptoms of allergies are present (itching, respiratory problems, etc.)
Symptoms Occur at therapeutic doses and below
Resolution of all symptoms occurs within days or weeks of stopping the drug
Chemical cross-reactivity may be present

Question 4

AERD Triad

Answer 4

Asthma + Nasal Polups + Sinusitis

Question 5

Can an angioedema patient use ARBs?

Answer 5

No, ARBs exacerbate Angioedema

Question 6

How to treat Anaphylaxis

Answer 6

IV fluids
Epinephrine
Oxygen

Question 7

PCN Skin Testing

Answer 7

Histamine = Positive control
NS = Negative control
Put a few drops of the allergen on the skin and compare to positive and negative controls

Question 8

Type I Rxn

Answer 8

Clinical symptoms: uticaria and anaphylaxis
Immune cause: IgE
Ex: PCN
Future use? If the patient is desensitized

Question 9

Type II Rxn

Answer 9

Clinical symptoms: Hemolytic anemia, AIN (Acute Interstitial Nephritis)
Immune Cause: IgG
Ex: PCN
Future use? No

Question 10

Type III Rxn

Answer 10

Clinical symptoms: Delayed Fever, Arthralgial
Immune Cause: IgG
Ex: Phenytoin
Future use? No

Question 11

Type IVa Rxn

Answer 11

Clinical Symptoms: Contact Dermatitis, PPD Rxn
Immune Cause: TH1
Ex: Latex
Future use? No

Question 12

Type IVb Rxn

Answer 12

Clinical Symptoms: Delayed MP rash
Immune Cause: TH2
Ex: Sulvonamides
Future use? May reuse

Question 13

Type IVc Rxn

Answer 13

Clinical Symptoms: SJS, TEN, CD
Immune cause: CTC
Ex: Sulfonamides
Future use? No

Question 14

Type IVd Rxn

Answer 14

Clinical symptoms: psoriasis
Immune cause: CD8
No Example or info about future use