Background: The aim of this study was to identify factors responsible for childhood-onset persistent asthma and childhood-onset asthma relapsing in adulthood.
Methods: We compared a number of potential risk factors for asthma among 608 patients with childhood-onset persistent asthma (onset at 15 years of age or younger) and 286 patients with childhood-onset asthma (onset at 20 years or younger) that had relapsed after a period of remission longer than 2 years.
Results: Multiple linear regression analysis revealed that the factors associated with childhood-onset persistent asthma were a past or present history of allergic rhinitis (p=0.001) and high serum total IgE concentration (> or =300 IU/ml; p=0.007). The factors associated with relapse of childhood-onset asthma were female sex (p=0.001), younger onset age (p=0.036), and smoking (current or former; p<0.001).
Conclusion: Our findings indicate that a past or present history of allergic rhinitis and high serum IgE level are significant risk factors for childhood-onset persistent asthma, and that female sex and a history of smoking are risk factors for relapse of childhood-onset asthma. Fortunately, exposure to tobacco smoke is a controllable risk factor.