Hypersensitivity And Allergy

Question 1

What is allergy/ hypersensitivity?

Answer 1

Foreign material recognise but self material damaged

Question 2

What is autoimmunity?

Answer 2

Self material recognised, self material damaged

Question 3

What is type 1 allergic tissue damage called?

Answer 3

Reaginic or atopic

Question 4

What happens if someone produces large amounts of IgE that recognises pollen?

Answer 4

Activates IgE covered mast cells - inflammatory response

Question 5

What causes smooth muscle contraction (wheezing) in people with pollen allergies

Answer 5

2 IgEs interact with same antigen triggering inflammatory mediators- increase vasodilation and permeability of blood vessels and odema. Resulting in smooth muscle contraction (wheezing)

Question 6

What is odema?

Answer 6

Movement of plasma and leucocytes int tissue

Question 7

What are the first mediators of allergic response? How long do they take?

Answer 7

Preformed granules mediators- tryptase, heparin, histamine. 5 min

Question 8

What are the second mediators of allergic response?

Answer 8

Newly generated mediators- arachidonic acid (5-30 min), leukotrienes and prostaglandins

Question 9

What is the 3rd response to allergic reaction?

Answer 9

Cytokines- take hours.

Question 10

How do th2 cells cause an atopic response?

Answer 10

If a th2 cell is sensitive to an antigen it will produce IL-4 that will promote B cells to produce antibodies against it- also produces Il-5 - eosinophils

Question 11

What type of allergic response are food allergies and allergic rhinitis?

Answer 11

Type 1

Question 12

In what test will you get a localised wheel and flare?

Answer 12

Skin prick test. If mast cells in tissue are sensitive to allergen- localised wheel and flare

Question 13

What is type 2 allergic response?

Answer 13

Reaction to cell surface antigens- eg good pastures disease

Question 14

What is a type 3 allergic response?

Answer 14

Immune complex deposition- eg. SLE

Question 15

What is type 4 allergic response?

Answer 15

T-cell mediated. Eg. Contact dermatitis

Question 16

What is atopy?

Answer 16

Family or personal tendency to produce IgE to allergies

Question 17

What is sensitisation?

Answer 17

IgE response to allergen- blood tes. Can be sensitised but not allergic

Question 18

Anaphylaxis?

Answer 18

Potentially life threatening allergic reaction- due to cross linking of of IgE bound to mast cell receptors

Question 19

What is allergy??

Answer 19

Disease following immune response to otherwise innocuous antigen

Question 20

Anaphylactoid?

Answer 20

Clinically like anaphylaxis but not IgE mediated - release of mast cell contents without cross linking of IgE

Question 21

What is intolerance?

Answer 21

Non immune related reaction

Question 22

What two controls are used in a skin prick test?

Answer 22

1) histamine test- make sure patient isn’t taking antihistamines
2) control- nothing- to make sure patient isn’t reacting to prick itself

Question 23

How do you treat anaphylaxis (at first)?

Answer 23

Oxygen treatment- lay down. Treat with adrenaline if signs of shock

Question 24

During anaphylaxis if no improvement in 5 min what do you treat with?

Answer 24

Antihistamine

Question 25

What treatment should a patient t be given to prevent a delayed reaction? (Allergy)

Answer 25

Hydrocortisone - reduces redness and swelling- it is a steroid

Question 26

How do corticosteroids work to suppress inflammation?

Answer 26

Mimic effect of hormones produced by adrenal glands- suppress immune system. Reduce production of chemicals that cause inflammation

Question 27

What is an epipen?

Answer 27

A self administered adrenaline device

Question 28

Should you treat adrenaline though an IV?

Answer 28

No- always IM

Question 29

What is urticaria?

Answer 29

Chronic or acute (

Question 30

How do you treat chronic urticaria/angiodema?

Answer 30

Antihistamines for 6mts-1yr. Or T cell inhibitors- cyclosporine

Question 31

What is cyclosporine?

Answer 31

A t-cell inhibitor.

Question 32

What do you do if someone has angiodema without urticaria?

Answer 32

Check c3, c4, c1 inhibitor levels

Question 33

What percentage of the U.K. Suffer from allergic rhinitis?

Answer 33

26%

Question 34

What can you use to look up a nostril?

Answer 34

An otoscope

Question 35

How is intermittent and persistent rhinitis divided?

Answer 35

Intermittent. = less than 4 days a week or less than 4 weeks at a time. Mild. = normal sleep and life. Moderate = abnormal sleep and life

Question 36

What percentage of children and adults have food allergies?

Answer 36

4% children and 3% adults

Question 37

Give an example of a non immune based food allergy.

Answer 37

Monosodium glutamate- in Chinese foods. Seaweed and tomatoes. Cause headaches, nausea and sweating

Question 38

What causes oral allergy syndrome?

Answer 38

Local oral symptoms after eating certain foods- veg nuts. Only raw food. Cross reactivity with pollens

Question 39

What are the two types of vasoactive amines that can cause headaches or palpitations?

Answer 39

Monoamines- chocolate Stilton red wine

Tyramine- yeast extract, soy sauce

Question 40

What causes coeliac disease?

Answer 40

Due to antibodies to tissue transglutaminase (TTG)

Question 41

What is involved in desensitisation?

Answer 41

Weekly injections for 15 weeks and 6 weekly injections for 3 years