A large study of more than 19,000 people in 18 different countries was conducted, and the results published in 2002 in the Journal of Allergy and Clinical Immunology 110:285-92. In addition to several European countries, the study included data from the United States, Australia, New Zealand and India. The study looked at the association between household characteristics such as dampness, mold exposure and dust mite levels and asthma in adults. Again, the findings are clear: "Results: Fitted carpets and rugs in the bedroom were related to fewer asthma symptoms and bronchial responsiveness…."
Overall, 39 173 individuals were treated with either SCIT or steroids; % received only steroids, and % received SCIT and/or steroids. The steroid-to-SCIT ratio was 14 : 1 ( P < ). The mean annual steroid injections were in the steroid-only group and in the SCIT group ( P < ). Of the SCIT-treated individuals, 84% did not need steroids after SCIT treatment ( P < ). The hazard ratios of receiving steroids after SCIT against grass, birch or both were , and , respectively ( P < ), when compared with the steroids-only group. The maximum hazard reduction was obtained if patients responded well to SCIT treatment after one to 3 years.
The proposed dose could be administered in all patients. No local reactions >5 cm occurred during the clustered injections. In 3 patients (10%) late mild local reaction was observed at the mL dose at two weeks (mean wheal size: cm). No systemic adverse reactions were observed throughout the study.
Regarding the need for medication, at baseline all patients were taking antihistaminics and nasal steroids. Eleven patients also needed ß2-agonists on demand. After a year of follow-up, six patients (20%) did not require any additional treatment, 22 patients (73%) only needed antihistaminics and 7 of them (23%) plus ß2-agonists on demand. Finally, in two patients (7%) it was not possible to decrease the initial treatment.