LIFE SCIENCE

Detailed explanation-1: -Allergic reactions are the result of the production of specific IgE antibody to common, innocuous antigens. Allergens are small antigens that commonly provoke an IgE antibody response. Such antigens normally enter the body at very low doses by diffusion across mucosal surfaces and therefore trigger a TH2 response.

Detailed explanation-2: -Type I hypersensitivity is also known as an immediate reaction and involves immunoglobulin E (IgE) mediated release of antibodies against the soluble antigen. This results in mast cell degranulation and release of histamine and other inflammatory mediators.

Detailed explanation-3: -Type II hypersensitivity reaction refers to an antibody-mediated immune reaction in which antibodies (IgG or IgM) are directed against cellular or extracellular matrix antigens, resulting in cellular destruction, functional loss, or tissue damage.

Detailed explanation-4: -The immediate hypersensitivity response is responsible for allergic disease and anaphylaxis. It is mediated by IgE antibody, and is triggered by binding of antigen to IgE molecules on the surfaces of mast cells.