A double-blinded, comparative study of the effects of short preseason specific immunotherapy and topical steroids in patients with allergic rhinoconjunctivitis and asthma

Abstract

Background: Both specific immunotherapy (SIT) and nasal steroid (NS) have been shown to effectively reduce symptoms of allergic rhinitis. Although a number of investigators have convincingly shown anti-inflammatory effects of both treatments in separate studies, few comparative studies have been performed.

Objective: The purpose of this study was to compare the effects of preseason SIT with a standardized allergen extract and NS in seasonal allergic disease (rhinoconjunctivitis and asthma).

Methods: We examined 41 patients allergic to birch pollen, 21 with rhinoconjunctivitis and 20 with both rhinoconjunctivitis and asthma; they were treated in a randomized, double-blinded comparative study with birch SIT and NS (budesonide 400 microg daily). Bronchial hyperresponsiveness was measured before and during the season. Changes in eosinophil number, eosinophil cationic protein, and eosinophil chemotactic activity (ECA) in peripheral blood were investigated.

Results: Symptoms of rhinoconjunctivitis increased significantly less in the NS-treated patients than in the SIT-treated patients during the final 2 weeks of the season (P = .03 and P = .04, respectively). Seasonal peak expiratory flow values decreased significantly only in the NS-treated patients (P = .01). In the NS-treated patients, bronchial hyperresponsiveness increased significantly during the season (P = .0001); however, SIT treatment prevented seasonal PC(20) increase in the asthmatic patients. Measurement of blood eosinophils, eosinophil cationic protein, and eosinophil chemotactic activity demonstrated significant seasonal increase only in the NS-treated asthmatic patients.

Conclusion: Treatment with NS was more effective than short-course preseason SIT in reducing symptoms of rhinoconjunctivitis; however, the 2 therapies were equivalent in terms of the need for rescue medication. SIT prevented seasonal increase in bronchial hyperresponsiveness, eosinophil number, eosinophil cationic protein, and eosinophil chemotactic activity only in asthmatic patients. The mechanisms underlying bronchial hyperresponsiveness developing during allergen exposure in rhinitis might be different from those operating in asthma.