PATHOLOGY

Detailed explanation-1: -There are two IgE receptors: FcRI is the high-affinity IgE receptor that is expressed by mast cells and basophils and by dendritic cells and Langerhans cells in the skin.

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: -IgE is produced by plasma cells located in lymph nodes draining the site of antigen entry or locally, at the sites of allergic reactions, by plasma cells derived from germinal centers developing within the inflamed tissue.

Detailed explanation-4: -Type I reactions (i.e., immediate hypersensitivity reactions) involve immunoglobulin E (IgE)–mediated release of histamine and other mediators from mast cells and basophils.