L10- Hypersensitivity reactions

Question 1

What is the type 1 hypersensitivity reaction?

Answer 1

Reaction to an allergen where mast cells are activated
Immediate reaction or late reaction
e.g asthma, nut allergies, bee sting

Question 2

What are the treatments for type 1 hypersensitivity reaction?

Answer 2

• Avoid allergen
• Corticosteroids
• Antihistamines
• Leukotriene receptor antagonists (montelukast)
• Injected epinephrine (emergency)

Question 3

What is the type 2 hypersensitivity reaction?

Answer 3

Antibody dependent cell mediated cytotoxicity
Antibodies (IgG and IgM) bind to antigen and are recognised by NK cells
The cell bearing the antigen is (wrongly destroyed)

Question 4

What are the treatments for type 2 hypersensitivity reaction?

Answer 4

• Avoid allergen
• Corticosteroid
• Azathioprine- prevents B cell prolif

Question 5

What are type 3 hypersensitivity reactions?

Answer 5

Excess antigen leads of accumulation of antigen-immune complexes in blood and tissues
Leading to an immune response e.g farmers lung

Question 6

What are the treatments for type 3 hypersensitivity reactions?

Answer 6

• Avoid allergen
• Corticosteroids
• Cromolyn sodium (interferes with release of inflammatory mediators from mast cells)

Question 7

What are type 4 hypersensitivity reactions?

Answer 7

Delayed reaction that takes weeks to develop and is mediated by activated T cells which destroy cells presenting the antigen
e.g MS, RA

Question 8

What are the treatments for type 4 hypersensitivity?

Answer 8

• Avoid allergen
• Corticosteroids
• Immunosuppressants (monoclonal antibodies)