Skin test demonstrates all types of hypersensitivity except:
High-Yield Explanation
Ans: b (type 2)Ref: Kuby's Immunology, 6th ed. Pg. 371-396.Hypersensitivity* Type I hypersensitivity - Ig E mediated- Causes systemic anaphylaxis and localized atopy- Detection includes skin testing by intradermal injection or by superficial scratching which helps in screening of allergens* Type II hypersensitivity- antibody mediated cytotoxicity- Causes transfusion reactions, haemolytic disease of newborn, drug induced haemolytic anaemia etc- No skin test is used for detection* Type II hypersensitivity- immune complex mediated- Causes arthus reaction and serum sickness- It can be as a result of injection of antigen* Type IV hypersensitivity - delayed type- Contact dermatitis, granuloma etc- Can be detected by skin tests and patch tests.