Allergic rhinitis: Epidemiology and natural history

Establishing a reliable estimate of the prevalence of allergic rhinitis is difficult; prevalence estimates range from as low as 4% to more than 40%. E pidemiology studies suggest the prevalence of allergic rhinitis in the Unit ed States and around the world is increasing. The cause of this increase is unknown; however, contributing factors may include higher concentrations o f airborne pollution, rising dust mite populations, less ventilation in hom es and offices, dietary factors, and the trend toward more sedentary lifest yles. Allergic rhinitis symptoms typically begin in childhood and adolescen ce and continue into adulthood In general, allergic rhinitis symptoms slowl y improve and skin-test reactivity tends to wane with increasing age. There is a significant trend or symptom improvement with younger age of onset of allergic rhinitis. As the complicated etiology of allergic rhinitis become s better understood, it may be possible to reverse the trend for increased prevalence.