Allergy

Question 1

What substances are released from mast cell degranulation in an allergic response?

Answer 1

-Histamine! (Tryptase, Hydrolase)

Later-> Secreted inflmmatory mediators
Prostaglandins, cytokines, leukotrienes

Question 2

What does release of histamine cause?

Answer 2

• Bronchial smooth muscle contraction
• Vasodilation
• Separation of endothelial cells (Hives)
• Pain and itching

Question 3

List some common food allergies

Answer 3

Milk, Eggs, Peanuts, Tree Nuts, Soya, Wheat, Fish, Sesame

Question 4

What are some advantages of skin-prick testing in allergy?

Answer 4

• Easy to perform
• Non-invasive
• Immediate results
• Cheap
• Negative result is excellent predictor of negative IgE mediated food reaction

Question 5

What are some disadvantages of skin-prick testing in allergy?

Answer 5

• Must stop antihistamines 48hrs prior
• Broken skin
• Theoretical risk of reactions
• Dermatographism
• Over-interpretation of positive results
• Avoid random tests

Question 6

What are some advantages of specific IgE in allergy?

Answer 6

• No-need to stop antihistamines

- No risk of reactions

Question 7

What are some disadvantages of specific IgE in allergy?

Answer 7

• Expensive and invasive
• Delay in obtaining results
• Less sensitive and specific than SPT
• Highly unreliable results in eczema

Question 8

What is the gold standard testing method of testing food allergy?

Answer 8

Oral food challenge

Question 9

If no allergen is found, what is the management for long term allergies?

Answer 9

-Regular non-sedating anti-histamines

+Leukotriene antagonist or H2 receptor antagonist

Question 10

What may adrenaline pens potentially interact with?

Answer 10

B-blockers

Tricyclics

Question 11

What are the effects of adrenaline in anaphylaxis?

Answer 11

• Reverses peripheral vasodilation
• Increases peripheral vascular resistance
• Improves BP and coronary perfusion
• Decreases angioedema
• Causes bronchodilation
• Decrease release of inflammatory mediators

Question 12

What condition may present similar to allergy but cause mainly oral symptoms?

Answer 12

Oral Allergy Syndrome

Itching, mouth swelling, tongue discomfort etc

Question 13

What treatment is suggested fro oral allergy syndrome?

Answer 13

Antihistamines
Avoidance
(Unlikely to cause anaphylaxis)

Question 14

What is the management for egg allergy?

Answer 14

• Avoidance
• Re-introduction
• Egg ladder

Question 15

What are some symptoms of IgE mediated Cow’s milk allergy?

Answer 15

• Vomiting

- Occasionally diarrhoea

Question 16

What are some symptoms of non-IgE mediated Cow’s milk allergy?

Answer 16

• Varying presentations

- Diarrhoea, vomiting, irritability, infantile eczema, bloating, bleeding PR

Question 17

What is the management of non-IgE/IgE mediated Cow’s milk allergy?

Answer 17

• Maternal avoidance of Cow’s Milk (need to supplement Calcium and Vit D)
• EHF formula
• AA formula if not tolerated
• Soya Milk > 1 year of age or not tolerated above