Background: Enzyme potentiated desensitization, in which ß-glucuronidase (BG) is administered with low doses of mixed allergens, was proposed in the 1970s for specifi c immunotherapy. The BG currently commercially available in a purifi ed and standardized preparation devoid of any allergen has been suggested as a regulator in the allergic immune response, acting on the cytokine-network of type 2 helper T cells. A double-blind
trial with a single-dose of BG proved effective in preventing symptoms in adult patients with rhinoconjunctivitis due to grass pollens.

Objective: The aim of this randomized double-blind placebo-controlled trial was to confi rm the safety and effectiveness of double-dose intradermal BG immunotherapy in preventing symptoms in children suffering from chronic rhinoconjunctivitis and/or asthma due to dust mite.

Method: We randomized 125 children with dust-mite related chronic rhinoconjunctivitis and/or asthma to the BG treated group (67) or the placebo group (58). All patients were screened before treatment (T0), at BG or placebo administration (T1 and T3), and at 3 and 9 months after T1 (T2 and T4). Drug intake and bronchial, nasal and ocular symptoms were recorded in a diary.

Results: Patients in both groups completed the study and BG treatment was well tolerated without side effects. Significant differences in symptoms were observed, in particular for conjunctivitis (P = .008). The total drug intake for allergic symptoms was signifi cantly lower in the treated group than in the placebo group (P < .01).

Conclusions: BG immunotherapy is effi cacious, safe, and well tolerated in allergic children. Moreover, good compliance with the administration of 2 doses per year and the lack of signifi cant side effects makes the benefit/risk ratio of this treatment particularly favorable.

Key words: ß-glucuronidase. Immunotherapy. Children. Allergic diseases.