Effects of sublingual immunotherapy in patients sensitised to Ambrosia. An open controlled study

Background: allergy to Ambrosia is a disease of growing importance in Europe. Injective and noninjective immunotherapy have been recognised as safe and effective but no evidence is currently available for sublingual immunotherapy (SLIT) in patients sensitised to Ambrosia. This study was planned to assess the effects and the safety of SLIT in patients clinically sensitised to Ambrosia. Methods: 19 patients clinically sensitised to Ambrosia and treated with SLIT were compared to 14 patients treated only with drugs. Diary cards with symptoms and drug consumption were filled-in by patients during the pollen season whereas specific nasal challenge and skin prick test were run two months before and after the pollen season. Patients and doctors were also asked to express their subjective assessment about symptoms and drug consumption during the season. Results: SLIT-treated patients had less symptoms and a significantly minor drug intake (p = 0.04) as compared to untreated patients. Nasal challenge test improved significantly in the SLIT group (p = 0.0001) but not in the control group (p = 0.6875) with a significant difference between groups at the end (p = 0.0413) but not at the beginning of the trial (p = 0.213). The decrease in skin reactivity was significant in the control group (p = 0.0186) and highly significant in the SLIT group (p < 0.0001), with no difference between groups (p = 0.2987). Subjective assessment from both patients and doctors was favorable to SLIT (p = 0.0005 for symptoms; p = 0.0019 for drug consumption). Only one minor local side effect was registered during SLIT. Conclusions: according to our data, SLIT in patients allergic to Ambrosia is safe and able to improve both subjective and objective parameters.