Preventive effects of sublingual immunotherapy in childhood: an open randomized controlled study.

Background Sublingual immunotherapy (SLIT) has been proved to be effective in allergic rhinitis and asthma, but there are few data on its preventive effects, especially in children. Objective To evaluate the clinical and preventive effects of SLIT in children by assessing onset of persistent asthma and new sensitizations, clinical symptoms, and bronchial hyperreactivity. Methods A total of 216 children with allergic rhinitis, with or without intermittent asthma, were evaluated and then randomized to receive drugs alone or drugs plus SLIT openly for 3 years. The clinical score was assessed yearly during allergen exposure. Pulmonary function testing, methacholine challenge, and skin prick testing were performed at the beginning and end of the study. Results One hundred forty-four children received SLIT and 72 received drugs only. Dropouts were 9.7% in the SLIT group and 8.3% in the controls. New sensitizations appeared in 34.8% of controls and in 3.1% of SLIT patients (odds ratio, 16.85; 95% confidence interval, 5.73-49.13). Mild persistent asthma was less frequent in SLIT patients (odds ratio, 0.04; 95% confidence interval, 0.01-0.17). There was a significant decrease in clinical scores in the SLIT group vs the control group since the first year. The number of children with a positive methacholine challenge result decreased significantly after 3 years only in the SLIT group. Adherence was 80% or higher in 73.8% of patients. Only 1 patient reported systemic itching. Conclusions In everyday clinical practice, SLIT reduced the onset of new sensitizations and mild persistent asthma and decreased bronchial hyperreactivity in children with respiratory allergy.