BDNF and allergic rhinitis: Allergic rhinitis manifests as an allergic inflammatory response, an IgE-mediated reaction involving a complex interaction between inflammatory cells including eosinophils and mast cells, their released inflammatory cytokines, proinflammatory neuropeptides which promote vasodilation and plasma extravasation and neurotrophins which prolong survival of inflammatory cells and contribute to hypersensitivity [4].