Definition:

Allergic rhinitis (AR) is an inflammation of nasal mucosa mediated by IgE-associated processes, which is characterised by pruritus, sneezing, rhinorrhoea, and nasal congestion. The development of AR entails a complex interaction between genetic predisposition and environmental exposure to different factors, of which the most important is the implicated allergen. Single-nucleotide polymorphism studies involving genes encoding for molecules implicated in the pathogenesis of AR have also been made. Such molecules comprise chemokines and their receptors, interleukins and their receptors, eosinophil peroxidase and leukotrienes, among others.