[Variable prevalence of allergic rhinitis and risk factors affecting the prevalence].

Allergic rhinitis is described as a chronic inflammation of the nasal mucosa causing rhinorrhea, sneezing, nasal congestion and itching, often characterized with conjunctival injection and ocular itching. The prevalence of pediatric allergic rhinitis has recently shown a sharp increase throughout the world. However, there are significant differences among the regions, thus indicating to the influence of varying genetic and environmental factors upon the development of allergic rhinitis. This regional difference is mainly related to the 'western diet' and 'western lifestyle', with its swift changes in environmental and behavioral factors, besides a genetic predisposition. Some main and potential risk factors contributing to the development of allergic rhinitis are still unclear. In this review, we discuss mostly well known and some emerging new risk factors in the light of recent literature.