How do S&S of immediate HS reaction occur?

➢ On subsequent exposure, allergens bind to multiple IgE molecules on mast cells, cross-linking the IgE molecules. ➢ Within minutes, this cross-linking of IgE activates the mast cells and triggers degranulation; a reaction in which the contents of the granules in the mast cell are released into the extracellular environment. ➢ The chemical mediators released by mast cells collectively cause the inflammation and signs and symptoms associated with type I HS reactions