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.