What type of hypersensitivity is associated with anaphylaxis?

Anaphylaxis is a severe and potentially life-threatening allergic reaction that occurs rapidly after exposure to an allergen. This condition is primarily associated with Type I hypersensitivity reactions, also known as immediate hypersensitivity reactions.

In Type I hypersensitivity, the immune system overreacts to a normally harmless substance (the allergen) such as food, pollen, or insect venom. Upon first exposure to an allergen, the body produces specific immunoglobulin E (IgE) antibodies. These IgE antibodies bind to mast cells and basophils. Upon subsequent exposure to the same allergen, the allergen binds to the IgE on the surface of these cells, leading to their activation and degranulation. This process releases a variety of mediators, including histamine, leukotrienes, and prostaglandins, which cause the various symptoms associated with anaphylaxis, such as difficulty breathing, swelling, and a drastic drop in blood pressure.

The other types of hypersensitivity (Type II, Type III, and Type IV) involve different immune mechanisms that are not characterized by the rapid systemic reactions observed in anaphylaxis. Type II involves antibody-mediated cell destruction; Type III is characterized by immune complex deposition; and Type IV is cell