Which among the following is an example for type I hypersensitivity reaction?
High-Yield Explanation
Type I reactions (ie, immediate hypersensitivity reactions) involve immunoglobulin E (IgE)-mediated release of histamine and other mediators from mast cells and basophils. Casoni's test, intradermal injection of hydatid fluid followed by production of wheal-flare reaction denotes hydatid infection. It is an immediate hypersensitivity reaction (Type I). Ahus reaction is a type of local type III hypersensitivity reaction. Type III hypersensitivity reactions are immune complex-mediated, and involve the deposition of antigen/antibody complexes. The autoimmune diseases, Myasthenia gravis, Graves' disease and Pernicious anemia are examples of Type II hypersensitivity.