Type 1 Hypersensitivity

Question 1

Symptoms of a type 1 H.S reaction?

Answer 1

Urticaria
Wheeze
D+V
Angioedema
Rhinoconjunctivits
ANAPHYLAXIS

Question 2

Additional symptoms of anaphylaxis?

Answer 2

Respiratory distress

Hypotension

Question 3

Preformed mast cell granules contain?

Answer 3

Histamine
Serotonin
Proteases

Question 4

Synthesised mast cell granules contain?

Answer 4

Leukotrienes
Prostaglandins
Bradykinin
Cytokines

Question 5

80% of these reactions present in the first year of life and defects in Beta defensin predispose to staph superinfection?

Answer 5

Atopic dermatitis (infantile eczema)

Question 6

Gold standard for diagnosing this is a double blind challenge test?

Answer 6

Food allergy

Question 7

Exposure to an allergen can induce an allergy to a related food?

Eg birch pollen and Rosacea fruit

Answer 7

Oral allergy syndrome

Question 8

Allergy to foods like chestnut, avocado, mango, kiwi, banana?

Answer 8

Latex food syndrome

Question 9

Can be seasonal (pollen), perennial (pets, dust) or occupational?

Answer 9

Allergic rhinitis

Question 10

Wheals resolve within 6 weeks and it is a clinical diagnosis?

Answer 10

Acute urticaria

Question 11

IgE mediated causes of mast cell degranulation?

Answer 11

Peanuts
Penicillin
Stings
Latex

Question 12

Non IgE mediated causes of mast cell degranulation?

Answer 12

NSAIDs
IV contrast
Opioids
Exercise

Question 13

Gold standard for investigating most allergies?

Answer 13

Skin prick test

Question 14

In an acute episode this is measured

Answer 14

Mast cell tryptase

Question 15

Positive control in skin prick test?

Answer 15

Histamine

Question 16

Negative control in skin prick test?

Answer 16

Dilutent

Question 17

Positive result of skin prick?

Answer 17

Wheal >= 2mm larger than negative control

Question 18

What must be stopped before the skin prick test?

Answer 18

Antihistamines must be stopped 48 hours before

*corticosteroids ok

Question 19

What test is used when antihistamines cannot be stopped before a skin prick or when there is a history of anaphylaxis?

Answer 19

RAST

Question 20

What does RAST measure?

Answer 20

IgE specific to an allergen

Question 21

What test measures for a specific protein of a specific allergen to predict a response?

Answer 21

Component resolved diagnosis

Question 22

Ara h 2 indicates?

Answer 22

High risk anaphylaxis to peanuts

Question 23

Ara h 8 indicates?

Answer 23

Likely local reaction to nuts only

Question 24

A negative skin prick tells you?

Answer 24

That the reaction is not IgE mediated

Question 25

What is type 1 H.S?

Answer 25

First exposure to allergen leads to production of IgE which bings mast cells and basophils via FcR

Second exposure leads to crosslinking resulting in degranulation of mast cells

Mediators released cause vasodilation, increased vascular permeability and smooth muscle contraction