Type I Hypersensitivity is an immediate allergic reaction mediated by IgE antibodies that occur upon exposure to a specific antigen, leading to symptoms like sneezing, itching, and anaphylaxis in severe cases. It involves the release of histamine and other chemicals from mast cells and basophils.
Topic 21.6: 21.6 Diseases Associated with Depressed or Overactive Immune Responses
Unit 21