ENT - allergy

Question 1

Define allergy

Answer 1

Chronic condition involving abnormal hypersensitive reaction produced by the immune system to an ordinarily harmless antigen called anallergen

Question 2

What are the 2 types of rhinitis

Answer 2

ALLERGIC RHINITIS & NON-ALLERGIC RHINITIS

Question 3

Allergic rhinitis is also known as

Answer 3

Hayfever

Question 4

Define rhinitis

Answer 4

Nasal mucosa inflammation

Question 5

Define allergic rhinitis

Answer 5

Nasal mucosa inflammation due to an allergen - e.g. pollen, cat hair, dust

Question 6

Immediate symptoms of allergic rhinitis (4)

Answer 6

Itchy nose
Sneezing
Blocked nose
Rhinorrhoea (nasal discharge)

Question 7

Late symptoms of allergic rhinitis (3)

Answer 7

Chronic obstruction
Hyposmia (Reduced smell)
Hyper-reactivity

Question 8

Pathophysiology of allergic rhinitis (type 1 hypersensitivity reaction) (2)

Answer 8

Sensitisation to the allergen
-plasma cells produce specific IgE in response to allergen and IgE binds to mast cells

Re-exposure to the allergen

• stimulates that specific IgE to act against the allergen
• mast cell degranulation

Question 9

What do mast cells contain (4)

Answer 9

Histamine, leukotrienes, prostaglandins, chemotactic factors

Question 10

Effect of histamine release in allergic rhinitis

Answer 10

Vasodilation –> increasing vascular permeability

Question 11

Effect of leukotriene release in allergic rhinitis

Answer 11

promotes inflammation by activating neutrophil production and recruiting them to the area

Question 12

Effect of prostagrandin release in allergic rhinitis (2)

Answer 12

Smooth muscle contraction

Vasodilation

Question 13

Effect of chemotactic factor release in allergic rhinitis

Answer 13

Leukocyte infiltration (esp eosinophils)

Question 14

2 stages of type 1 hypersensitivity reaction

Answer 14

Acute (immediate response)
-minutes after exposure

Late phase response
-2-4hrs after exposure

Question 15

What occurs in the acute immediate response of type 1 hypersensitivity reactions

Answer 15

Mast cell degranulation –> vasodilation, mucous secretion, nerve stimulation & smooth muscle contraction

Question 16

What occurs in the late phase response of type 1 hypersensitivity reactions

Answer 16

Migration of other leukocytes (e.g. neutrophils, lymphocytes, eosinophils and macrophages) to the initial site

Question 17

Name 3 factors that produce allergic reactions, e.g. eczema, asthma, food allergies

Answer 17

Host factors
Environmental factors
Occupational factors

Question 18

List some host factors that contribute to allergic reactions (3)

Answer 18

Inherited
Race
Age

Question 19

List some environmental factors that contribute to allergic reactions (3)

Answer 19

Exposure to infectious diseases during early childhood
Pollution
Dietary changes

Question 20

List some occupational factors that contribute to allergic reactions (3)

Answer 20

Flour - bakers
Latex - health workers
Wood dust

Question 21

Define intermittent allergic rhinitis

Answer 21

Symptoms <4 days per week OR <4 consecutive weeks

Question 22

Define persistent allergic rhinitis

Answer 22

Symptoms >4 days per week AND >4 consecutive weeks

Question 23

Investigations of allergic reactions (5)

Answer 23

Skin test
RAST (radioallergosorben test)
Total serum IgE
Nasal allergen challenge
Nasal cytology

Question 24

How does the skin test work

Answer 24

Checks for immediate allergic reactions to as many as 40 different substances at once.

Small amounts of different allergens are placed on an individual’s skin, usually with a pinprick.

If allergic to these substances, will develop itchyhivesat these sites

Question 25

How does the RAST (radioallergosorben test) work

Answer 25

Is a blood test so takes longer than skin test so skin test preferred Looking for presence and levels of IgE against specific allergens in the blood

Question 26

Negative RAST test = what concentration of IgE

Answer 26

Level 0: IgE <0.35kU/L

Question 27

Treatment of allergic reactions (3)

Answer 27

Avoid allergen Pharmacotherapy Immunotherapy

Question 28

Pharmacotherapy of allergic reactions (7)

Answer 28

Topical intranasal steroids Systemic Steroids Antihistamines - prevent vasoconstriction etc LTRA Sodium cromoglycate - inhibits degranulation of mast cells Allergen Immunotherapy Anti-IgE

Question 29

How is immunotherapy used to treat allergic reactions

Answer 29

Stops body from producing specific IgE against the allergen by stopping it from recognising it as a foreign antigen Patient is admitted to ITU and gradually increasing doses of the allergen are injected over 6 weeks for 3 consecutive years to allow immune system to become less sensitive to the allergen