Allergic reactions consist of sensitization upon exposure to an allergen with subsequent inflammation. Different inflammatory components are implicated, as are irritation or hyperresponsiveness, and involve neurogenic responses. The propensity to react with specific inflammation and nonspecific irritation to stimuli of triggering substances is influenced by genetic factors and varies greatly dependent upon the individual circumstances.
Induction of inflammation
In the induction of inflammation the allergen is taken up, processed and subsequently presented to the T-cells of the immune system. The T-cells orchestrate the inflammatory reaction, including regulation of the formation of specific IgE antibodies to the allergen. The IgE antibodies bound to mast cells trigger the release of vasoactive substances and mediators interacting with the surrounding tissue, resulting in symptoms. Both the number and the activity of the mast cells are stimulated by the T-cells. The T-cells also control the number and the activity of the eosinophils. Inflammation results in allergic symptoms.