Safety of sublingual immunotherapy in children with asthma

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.

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.

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.

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.