Randomized double-blind controlled study with sublingual carbamylated allergoid immunotherapy in mild rhinitis due to mites

Background: The clinical efficacy of sublingual immunotherapy (SLIT) in mite allergy and in mild disease is still a matter of debate, thus we performed a long-term clinical trial. Methods: The study was randomized, double-blind and placebo-controlled. After a 1-year assessment, 68 patients with mild rhinitis with/without asthma due to mites were randomized to drugs + placebo or drugs + SLIT for 2 years. Sublingual immunotherapy was given as soluble tablets of monomeric carbamylated allergoid. Clinical scores for asthma and rhinitis (0, absent to 3, severe) and drug consumption were assessed by diary card in the period November-February. Quality of life was assessed before and after each observation period and pharmaco-economy data were evaluated as well. Results: Fifty-six patients completed the study. The rate of dropouts was similar in the two groups. No relevant side effect was reported. There was a significant reduction of total clinical scores (P < 0.05) in the active group vs placebo at the first year, but not at the second whereas nasal obstruction significantly improved in both years (P < 0.05). The reduction of drug intake score was significant only at the first year. No change was observed concerning most of the Short Form-36 items, because at baseline all patients displayed a normal profile. A significant change in SLIT group was seen for the item 'change in health status'. The need for extra visits was significantly lower in the active group (25%vs 43%). Conclusion: Sublingual immunotherapy was clinically effective and safe in mite-induced mild disease.