Comparing the compliance to a short schedule of subcutaneous immunotherapy and to sublingual immunotherapy during three years of treatment.

Background: Allergen immunotherapy (AIT) in its two forms of subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) is an effective treatment of respiratory allergy, but is particularly concerned by the issue of compliance.
Objective: We aimed a real-life study at evaluating the compliance to SLIT and to SCIT administered by a short-course of four injections during a 3-year period of observation.
Methods: A group of 145 patients (79 males, 66 females, age ranging from 14 to 69 years), suffering from pollen-induced rhino-conjunctivitis with or without asthma, were included in the study. Following adequate education on AIT and according to patient's preference, 72 patients chose to be treated with short-course SCIT and 73 chose to be treated with SLIT. The latter was performed by allergen extracts from different manufacturers according to the suggested schedules.
Results: The rate of withdrawal was as follows: after one year, 15.6% for SCIT and 33.4 for SLIT; after two years, 25.6% for SCIT and 44.8% for SLIT; after three years, 26.7 for SCIT and 46% for SLIT. There was no significant difference in the rate of withdrawal between males and females. Regarding the safety, no systemic reaction requiring medical treatment was observed either in SCIT or SLIT group.
Conclusion: The findings of this study confirm that involving the patient in the choice of the route of administration is associated to a satisfactory compliance to AIT. In particular, more than 70% of patients treated with a short schedule of SCIT completed the three-years course of treatment that is recommended for AIT, while this goal was reached by 54% of SLIT treated patients.