The efficacy of sublingual immunotherapy for respiratory allergy is not affected by different dosage regimens in the induction phase

Background: Sublingual administration of allergens is a safe and effective alternative to subcutaneous immunotherapy in patients with respiratory allergies. A drawback to this therapeutic approach is the relatively long and complex management of the induction phase. Aim of the study: To determine whether different induction regimens affect the outcome of sublingual immunotherapy. Methods and results: Adult and pediatric patients with allergic rhinoconjunctivitis and/or asthma were included in the study. Ten subjects served as controls and received symptomatic treatments. Forty-three subjects were allocated to sublingual immunotherapy, with three different induction protocols (8-, 15-and 20-day, respectively). Symptom and medication scores, skin test results and (in asthmatic patients) FEV₁ values were monitored for two years. Adverse effects were recorded. All induction regimens produced a significant improvement in symptom and medication usage (p <0.0001); skin test scores decreased (p <0.0001) and FEV₁ improved (p <0.05). In contrast, symptom and skin test scores did not significantly change in controls. No relevant adverse effects were observed with any of the induction regimens. Conclusions: For patients with respiratory allergies, sublingual immunotherapy with an 8-day induction protocol is safe and effective. Our results encourage the usage of shorter induction regimens, which produce better compliance with this therapy.