Which among the following hypersensitivity cannot be detected by skin test
High-Yield Explanation
Ans b: (Ref: ROBBINS 7th edition-210)Type 1: Immediate hypersensitivity- Involves Ig E mediated release of histamine & other mediators from mast cells & basophilsEg: Skin tests-Casoni's testType 2: Antibody mediated - Involves IgG or IgM with subsequent complement fixationType 3: Immune compex mediated- Involve circulating Ag-Ab complex that deposit in venules with subsequent complement fixation* systemic- serum sickness -skin, joint, lungs, kidney, blood vessels* localized - arthus reaction - skinType 4: Delayed hypersensitivity-mediated by T cells Eg: Tuberculin tests, Lepromin tests"Examples of types of reationare given in previous, please go through it"