Safety of sublingual immunotherapy in children with asthma.

Introduction: Two previously published studies on sublingual immunotherapy (SLIT) did not report any serious adverse event associated with the local therapy; however, adverse events were observed in greatly variable percentages. The aim of the study was to evaluate the tolerability profile of sublingual swallow and spit immunotherapy in a large number of children treated for allergic asthma.

Methods: Adverse effects related to sublingual administration of allergen vaccines were evaluated in 354 children with allergic asthma. Each patient was followed for at least 37 months and received a monthly dose of major allergens (extract) in the range of 1.5-14.8mug, equivalent to 3-20 times the amount contained in the usual monthly maintenance injections via the subcutaneous routes.

Results: No adverse event was observed in 90.4% of the children. We observed 0.155 mild to moderate reactions per 1000 administrations. Dosage adjustment was required in 15 patients. In five children, immunotherapy was stopped as a precaution - one patient developed rhino-conjunctivitis, two patients developed urticaria, and two children developed wheezing. None of the reactions were due to dosage errors. No anaphylactic reaction or multiple-organ life-threatening events occurred.

Conclusions: The results of our study showed an incidence of mild to moderate unwanted effects of 9.6%, lower than that previously reported, and no life-threatening adverse effects. Nevertheless, asthma, urticaria, and rhinoconjunctivitis can occur. SLIT is quite a safe therapy for the treatment of allergic children with asthma; however, careful evaluation of the single patient is necessary since SLIT is self-administered and a cumulative monthly dose higher than that normally administered as an injection is usually attainable.