There is mounting evidence that successful allergen immunotherapy (SIT) functions through the induction of different subset of Treg including Foxp3 positive cells, therefore additional strategies to enhance this property are highly attractive. Based on previous findings we assumed that combine allergen immunotherapy with non-specific treatments such as glucocorticosteroids and vitamin D3 as well as montelukast sodium treatment might enhanced allergen tolerance induction and improved clinical effectiveness of allergen-specific immunotherapy