Allergen immunotherapy consists in the administration of the appropriate allergen to which the patient is hypersensitive. The objective is to induce immunological tolerance of the organism. In the present study, the effect of the administration of Phostal on the occurrence of seasonal symptoms of pollinosis in a group of 35 outpatients was observed during two years. The substance was administered according to the regular dosage schedule, all year round. The results of the study have demonstrated a significant effect of the product on the decrease in the occurrence of observed objective symptoms of the disease, starting already from the first year of treatment. This is in correlation with changes in the spirometric functions, selected laboratory parameters and results of the prick tests in the treated group in comparison to the control group.

        Key words: allergen immunotherapy – pollinosis – Phostal