Hypersensitivity

Question 1

Type I hypersensitivity reaction is what?

Answer 1

Anaphylaxis

Question 2

Mechanism of type I reaction

Answer 2

Antigen reacts with IgE bound to mast cells

Question 3

Examples of type I reaction

Answer 3

Anaphylaxis

Atopy (e.g. asthma, eczema, hayfever)

Question 4

Type II hypersensitivity reaction is what?

Answer 4

Cell bound

Question 5

Mechanism of type II hypersensitivity reaction

Answer 5

IgG or IgM binds to antigen on the cell surface

Question 6

Examples of type II hypersensitivity reaction

Answer 6

Autoimmune haemolytic anaemia
ITP
Goodpastures syndrome
Pernicious anaemia 
Acute haemolytic transfusions reaction 
Rheumatic fever
Pemphigus bullous / vulgaris

Question 7

Type III hypersensitivity reaction is what?

Answer 7

Immune complex

Question 8

Mechanism of type III hypersensitivity reaction

Answer 8

Free antigen and antibody (IgG, IgA) combine

Question 9

Examples of type III hypersensitivity reaction

Answer 9

Serum sickness
SLE
Post strep GN
Extrinsic allergic alveolitis (especially acute phase)

Question 10

Type IV hypersensitivity is what?

Answer 10

Delayed hypersensitivity

Question 11

Mechanism of type IV hypersensitivity

Answer 11

T cell mediated

Question 12

Examples of type IV hypersensitivity

Answer 12

TB skin reaction 
Graft vs host disease
Allergic contact dermatitis
Scabies
Extrinsic allergic alveolitis (especially chronic phase)
MS
GBS