Anaphylaxis

Question 1

Anaphylaxis may be defined as a severe, life-threatening, generalised or systemic hypersensitivity reaction. How common is anaphylaxis?

1 - 2 cases per 100,000
2 - 20 cases per 100,000
3 - 200 cases per 100,000
4 - 2000 cases per 100,000

Answer 1

2 - 20 cases per 100,000

Question 2

Anaphylaxis may be defined as a severe, life-threatening, generalised or systemic hypersensitivity reaction. What age is the peak incidence of anaphylaxis?

1 - 1-10
2 - 10-30
3 - 20-30
4 - 40-60

Answer 2

3 - 20-30

Question 3

Anaphylaxis may be defined as a severe, life-threatening, generalised or systemic hypersensitivity reaction. Is there a gender effect of anaphylaxis?

Answer 3

• no
• affects females and males equally

Question 4

In anaphylaxis do people have an allergic reaction they are exposed the first time to the allergen?

Answer 4

• no
• 1st = sensitisation
• 2nd = allergic reaction or even anaphylaxis

Question 5

The first time a patients body is exposed to an allergen the foreign allergen is phagocytosed by an antigen presenting cell (APC) before being presented to which cell?

1 - B cells
2 - cytotoxic CD8 T cells
3 - CD4 T helper cells
4 - natural killer cells

Answer 5

3 - TCD4 T helper cells

• APC activates T cell that then secretes inflammatory cytokines that activate B cells

Question 6

The first time a patients body is exposed to an allergen the foreign allergen is phagocytosed by an antigen presenting cell (APC) before being presented to CD4 T helper cells and inflammatory cytokines are released that activate B cells. These B cells then produce and secrete which antibodies?

1 - IgM
2 - IgE
3 - IgD
4 - IgA

Answer 6

2 - IgE

Question 7

Once B cell produce and secrete IgE antibodies they move around the body in the blood stream and bind to which 2 of the following immune cells?

1 - mast cells
2 - neutrophils
3 - basophils
4 - macrophages

Answer 7

1 - mast cells
3 - basophils

Both cells are full of granules that contain pro-inflammatory molecules

Question 8

The second time a patient is exposed to the same allergen, the body is already primed with IgE antibodies that are bound to mast cells and basophils. The allergen binds with the IgE antibodies and undergoes degranulation releasing which 2 of the following?

1 - histamine and CRP
2 - histamine and tryptase
3 - tryptase and CRP
4 - CRP and CK

Answer 8

2 - histamine and tryptase

Question 9

The second time a patient is exposed to the same allergen, mast cells are able to release what that causes vasoconstriction of smooth muscle in the airways and GIT?

1 - CRP
2 - histamine
3 - leukotrienes
4 - thromboxane

Answer 9

2 - histamine

Question 10

The second time a patient is exposed to the same allergen, in addition to causing vasoconstriction of smooth muscle in the airways and GIT, does histamine cause vasodilation or constriction of blood vessels?

Answer 10

• vasodilation

Question 11

The second time a patient is exposed to the same allergen, histamine induces vasodilation of blood vessels and causes what?

1 - increased blood flow to site of initial allergen exposure
2 - oedema and drop in blood pressure
3 - increase blood vessel diameter and permeability
4 - urticaria (hives)
5 - all of the above

Answer 11

5 - all of the above

Question 12

The second time a patient is exposed to the same allergen, in addition to histamine, what do mast cells secrete that is a protease and able to induce tissue damage?

1 - tryptase
2 - CRP
3 - leukotrienes
4 - thromboxane

Answer 12

1 - tryptase

Question 13

The second time a patient is exposed to the same allergen, in addition to histamine and tryptase, mast cells and basophils are able release cytokines IL-4 and IL-13 that tell B cells to produce more IgE and release TNF-a. But mast cells and basophils also secrete what else that is important for attracting immune cells?

1 - prostaglandins
2 - CRP
3 - leukotrienes
4 - thromboxane

Answer 13

3 - leukotrienes
- fatty acids

Recruit neutrophils, mast cells and eosinophils

Question 14

The second time a patient is exposed to the same allergen, mast cells and basophils secrete leukotrienes that attracts other immune cells. Is this a quick or slow response?

Answer 14

• slow response

Often occurs after the allergen is gone and are often not seen until hours after the initial reaction

Question 15

Which type of hypersensitivity is most commonly associated with anaphylaxis?

1 - IgE mediated hypersensitivity
2 - IgG mediated cytotoxic hypersensitivity
antibody-dependent cytotoxic hypersensitivity
3 - immune complex mediated
4 - cell mediated hypersensitivity

Answer 15

1 - IgE mediated hypersensitivity

Question 16

Is anaphylaxis always caused by a type I IgE mediated hypersensitivity?

Answer 16

• no

Some can be IgG hypersensitivity, such as those caused by a blood transfusion

Question 17

In a patient with anaphylaxis, what is the 1st thing we must do?

1 - perform ABCDE
2 - take blood
3 - request imaging
4 - request fluids and observations

Answer 17

1 - perform ABCDE

Question 18

Which of the following are clinical presentations of anaphylaxis?

1 - itchy rash (urticaria or erythema)
2 - vomiting and diarrhoea
3 - respiratory wheeze and dyspnoea (SOB)
4 - swelling of the throat and tongue with hoarse voice and stridor
5 - hypovolaemia and cardiovascular collapse
6 - all of the above

Answer 18

6 - all of the above

If there is no issues with ABC as part of the ABCDE, then the patient is unlikely to be having anaphylaxis

Question 19

In a patient who is anaphylactic we would do the usual ABCDE and put them on high flow oxygen. We then need to prescribe all of the following EXCEPT?

1 - Adrenaline (1:1000 1 mg/ml IM in adults)
2 - IV fluids: 0.5 L – 1.0 L of NaC l/ Hartmann’s (avoid colloids)
3 - aspirin
4 - Inhaled ß2 agonist (salbutamol)

Answer 19

3 - aspirin

• always refer to anaphylaxis guide

Question 20

In anaphylaxis all of the following should be given asap, but which is most important?

1 - high flow oxygen
2 - Adrenaline (1:1000 1 mg/ml IM in adults)
3 - IV fluid challenge: 500ml – 1000ml of NaC l/ Hartmann’s (avoid colloids)
5 - Inhaled ß2 agonist (salbutamol)

Answer 20

2 - Adrenaline (1:1000 1 mg/ml IM in adults)

Best location is anterolateral aspect of the middle third of the thigh.

Question 21

Adrenaline (1:1000 1 mg/ml IM in adults) is the most important medication given to a patient with anaphylaxis. How often can adrenalin be given?

1 - once only
2 - every 5 minutes
3 - every 30 minutes
4 - every hour

Answer 21

2 - every 5 minutes

Question 22

Prior to giving adrenaline, the patients legs should be raised during anaphylaxis. Why is this?

1 - more comfortable for patients
2 - reduces risk of oedema
3 - increases venous return and cardiac output
4 - all of the above

Answer 22

3 - increases venous return and cardiac output

Question 23

All of the following should be given during anaphylaxis. Organise the order of the following:

1 - IV fluids
2 - high flow oxygen
3 - adrenaline
4 - inhaled ß2 agonist (salbutamol)

Answer 23

3 - adrenaline
2 - high flow oxygen
1 - IV fluids
4 - inhaled ß2 agonist (salbutamol)

Question 24

Once a patient has stabilised following anaphylaxis, which 2 of the following should be performed?

1 - give antihistamines (preference to chlorphenamine = non-drowsy)
2 - give hydrocortisones
3 - test tryptase levels (high for 12h following anaphylaxis)
4 - blood transfusion to increase low BP

Answer 24

1 - give antihistamines (preference to chlorphenamine = non-drowsy)
3 - test tryptase levels (high for 12h following anaphylaxis)