Nasal immunotherapy at constant dosage: a double-blind, placebo-controlled study in grass-allergic rhinoconjunctivitis.

A preliminary open study showed that intranasal immunotherapy can be administered with a constant dosage scheduling, with good safety and efficacy. In the present study the efficacy of constant dosage intranasal immunotherapy has been evaluated on 43 grass-allergic rhinitis patients according to a double-blind placebo-controlled design. The product employed for the study had a formulation in powder, and was administrated by a nasal insufflator. Clinical efficacy was evaluated for each symptom, taking into consideration the severity of the symptom in relation to its frequency. Sneezing, rhinorrea, nasal blockage, eyes itching, and drug consumption were significantly improved in active-treated patients compared to placebo-treated. The safety of this treatment was good, the only adverse events observed being some local and mild symptoms. This immunotherapy was well-tolerated and easy to handle by the patients by self-administration.