EPIDEMIOLOGY OF PHYSICIAN-DIAGNOSED ALLERGIC RHINITIS IN CHILDHOOD

Objective. To investigate the natural history of and risk factors for allergic rhinitis in the first 6 years of life. Methods. Parents of 74 7 healthy children followed from birth completed a questionnaire when the child was 6 years old. Data were obtained regarding physician-diag nosed allergic rhinitis (PDAR), associated symptoms, and age at onset. Risk-factor data were taken from earlier questionnaires, and data reg arding immunoglobulin E (IgE) and skin-test reactivity were obtained a t age 6. Results. By the age of 6, 42% of children had PDAR. Children whose rhinitis began in the first year of life had more respiratory sy mptoms at age 6 and were more likely to have a diagnosis of asthma. Ea rly introduction of foods or formula, heavy maternal cigarette smoking in the first year of life, and higher IgE, as well as parental allerg ic disorders, were associated with early development of rhinitis. Risk factors for PDAR that remained significant in a multivariate model in cluded maternal history of physician-diagnosed allergy (odds ratio: 2. 2, 95% confidence interval: 1.35-3.54), asthma in the child (4.06, 2.0 6-7.99), and IgE greater than 100 IU/mL at age 6 (1.93, 1.18-3.17). Th e odds for atopic as opposed to nonatopic PDAR were significantly high er only among those with high IgE and those who had dogs. Conclusion. Allergic rhinitis developing in the first years of life is an early ma nifestation of an atopic predisposition, which may be triggered by ear ly environmental exposures.