B-Respiratory reactions
1. Sneezing
One of the most important reactions in a respiratory allergy is sneezing, which is not common in infections of the respiratory tract as it is in hypersensitivity reactions. In a respiratory infection, the antigen that triggers allergies contacts the epithelium of the respiratory tract and is recognized by a series of cells that react against it and trigger an inflammatory reaction along with other recruited cells. The cytokines released by these cells in the nasal cavity and the respiratory tract trigger an itching sensation in the nasal cavity that promotes sneezing.