Learning Objectives

• Describe the basic principles of the four main types of hypersensitivity I-IV and give clinical examples of each type:
  • Type I – immediate, allergy, mediated mainly by mast cells and IgE
  • Type II – cytotoxicity eg. transfusion reactions, haemolytic disease
  • Type III – immune complex deposition in tissues eg. Arthus reaction, serum sickness
  • Type IV – delayed reactions, mediated by T cells eg. tuberculin reaction, contact HS

Hypersensitivity Reactions

• what is a hypersensitivity reaction?
• what type of host do HS reactions occur in?
• what are the 2 phases of a HS reaction?
• what are the 4 types of HS reactions?
• Mechanisms of HS Reactions Summary
• compare type A vs type B adverse drug reactions?

Type I Hypersensitivity

• examples of type 1 I HS reactions?
• what are the main mediators of type I HS reactions?
• describe the mechanisms of the sensitisation phase of type I HS reactions?
• describe the mechanisms of the biphasic effector phase of type I HS reactions?
• what is atopy? atopic individuals have high levels of [what]?
• what effect does mast cell degranulation have on the GIT, airway, and blood vessels?
• Symptoms According to Route of Allergen Entry

Allergy & Anaphylaxis

• what is anaphylaxis? how is it different to an allergy?