Clinical Features Cannot Distinguish Allergic from Non-allergic Asthma in Children

OBJECTIVE: Environmental allergens are a major trigger of asthma, but not all asthmatics are allergic. This study was designed to review clinical characteristics in children with allergic and non-allergic asthma, based on responsiveness to allergy skin tests, in order to identify a combination of features that could distinguish allergic from non-allergic asthma in children. METHODS: Medical records of 321 children who had allergy skin testing were reviewed, and demographic and clinical data were compared between allergic and non-allergic patients. RESULTS: Approximately two-thirds of the asthmatic children had at least one positive skin test. These allergic patients were more likely to have a history of eczema or Medicaid insurance, but these findings had poor predictive value. There was no difference between allergic patients and non-allergic patients in terms of family history of atopy or asthma, home tobacco smoke exposure, age of onset of asthma, gender, rate of obesity, or asthma severity. Among the allergic asthma patients, neither the number of positive skin tests nor specific individual allergic sensitivities correlated with age of onset of asthma or asthma severity. CONCLUSIONS: This study failed to identify any combination of features that could reliably distinguish allergic from non-allergic asthma in children. Thus, all children with asthma should undergo allergy testing in order to identify potential allergic triggers in allergic patients and to avoid the institution of unnecessary environmental control measures in non-allergic patients.