Childhood allergic rhinitis predicts asthma incidence and persistence to middle age: A longitudinal study

Background: The association between allergic rhinitis and asthma is well documented, but the temporal sequence of this association has not been closely examined. Objective: We sought to assess the associations between childhood allergic rhinitis and (1) asthma incidence from preadolescence to middle age and (2) asthma persistence to middle age. Methods: Data were gathered from the 1968, 1974, and 2004 surveys of the Tasmanian Asthma Study. Cox regression was used to examine the association between childhood allergic rhinitis and asthma incidence in preadolescence, adolescence, and adult life. Binomial regression was used to examine the association between childhood allergic rhinitis and asthma beginning before the age of 7 years and persisting at age 44 years. Results: Childhood allergic rhinitis was associated with a significant 2- to 7-fold increased risk of incident asthma in preadolescence, adolescence, or adult life. Childhood allergic rhinitis was associated with a 3-fold increased risk of childhood asthma persisting compared with remitting by middle age. Conclusions: Childhood allergic rhinitis increased the likelihood of new-onset asthma after childhood and the likelihood of having persisting asthma from childhood into middle age. Clinical implications: Asthma burden in later life might be reduced by more aggressive treatment of allergic rhinitis in early life. (J Allergy Clin Immunol 2007;120:863-9.) Key words: Childhood allergic rhinitis, incident asthma, persisting asthma, effect modificatio