In children and adolescents with difficult-to-treat asthma, few data exist characterizing the relationships between basic patient characteristics (e.g., age, sex) and atopic indicators in asthma. These associations were examined in The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR), an observational study of a large cohort of patients with severe or difficult-to-treat asthma. To characterize allergy patterns and the relationship between total serum immunoglobulin E (IgE) and airflow in young patients with severe or difficult-to-treat asthma. A total of 1261 patients from the TENOR study were stratified into four age groups at baseline (6-8, 9-11, 12-14, and 15-17 yr). The objective was to characterize allergy patterns and the relationship between total serum immunoglobulin E (IgE) and ratio of pre-bronchodilator forced expiratory volume in 1 second to forced vital capacity (FEV(1) /FVC) in young patients with severe or difficult-to-treat asthma. The chi-square test for categorical variables and analysis of variance for continuous variables were used to identify significant differences among age groups. Multivariable linear regression was used to evaluate the association between IgE and FEV(1) /FVC. Allergic rhinitis was reported in approximately two-thirds of patients. Up to 25% of patients had atopic dermatitis, which differed across age groups in boys (p < 0.05). Positive allergen skin test rate differed across age groups in boys (p < 0.05). Rates of asthma triggers were higher and differed across age groups in girls (p < 0.05), particularly around menarche (12-14 yr). IgE levels were higher in boys and differed across age groups in boys (p < 0.01) and girls (p < 0.05). IgE was associated with a lower FEV(1) /FVC after adjusting for age and sex (p < 0.01). Severe or difficult-to-treat asthma in children and adolescents is characterized by high frequencies of comorbid allergic diseases, allergen sensitization, and high IgE levels. This burden is amplified by the association of more airflow limitation with higher IgE levels, suggesting the need for allergy evaluations.
© 2010 John Wiley & Sons A/S.