Lec 02: Anaphylaxis

Question 1

What is anaphylaxis?

Answer 1

a serious allergic reaction that is rapid in onset and may cause death

Question 2

(T/F) Anaphylaxis is a type 1 hypersensitivity reaction.

Answer 2

T

Question 3

What are the causes/triggers of anaphylaxis and anaphylactoid reactions?

Answer 3

food, drugs, stings, allergens, exercise, idiopathic

Question 4

What is the most common trigger of anaphylaxis?

Answer 4

food

Question 5

What is the most common manifestation of drug allergy?

Answer 5

urticaria

Question 6

What are the main mechanisms by which stimuli cause anaphylactoid reactions?

Answer 6

direct mast cell activation, disturbances in arachidonic acid metabolism

Question 7

What is the difference between true anaphylaxis and anaphylactoid reactions?

Answer 7

True anaphylaxis involves IgE antibodies binding to mast cells. Anaphylactoid reactions can be caused by alternative methods of getting mast cells to degranulate. The two are practically identical when observed clinically.

Question 8

What are the patient-related factors which may contribute to anaphylaxis?

Answer 8

age, asthma and other respiratory diseases, concomitant diseases, atopy, previous history of anaphylaxis, concurrent medications, exercise, infections, stress

Question 9

What are the two kinds of allergen?

Answer 9

complete protein, low molecular weight substances

Question 10

(T/F) Complete proteins are capable of eliciting a complete antibody response by themselves.

Answer 10

T

Question 11

What is the appropriate Th1 response to an allergen?

Answer 11

release of cytokines resulting in tolerance

Question 12

What type of cell encounters and identifies allergens?

Answer 12

antigen presenting cells (APCs) e.g. macrophages

Question 13

(T/F) Absence of cutaneous Ssx rules out anaphylaxis.

Answer 13

F

Question 14

What is the most common Ssx observed in anaphylaxis?

Answer 14

urticaria and angioedema

Question 15

How do you differentiate anaphylaxis from a vasovagal response based on observation of the CVS?

Answer 15

vasovagal response: BP and heart rate decrease

anaphylaxis: BP decreases, heart rate increases

Question 16

How is the vomit of an anaphylaxis patient described?

Answer 16

stringy

Question 17

What is the first-line treatment for anaphylaxis?

Answer 17

epinephrine

Question 18

(T/F) Steroids are an effective substitute for epinephrine in anaphylaxis.

Answer 18

F

Question 19

Which lab test would be most helpful to confirm the diagnosis of anaphylaxis?
A. serum specific IgE levels
B. skin testing
C. serum tryptase level
D. plasma histamine level

Answer 19

B.