Relevant Patient Benefit of Sublingual Immunotherapy with Birch Pollen Allergen Extract in Allergic Rhinitis: An Open, Prospective, Non-Interventional Study

桦树花粉过敏原提取物舌下免疫疗法对过敏性鼻炎患者的相关获益：一项开放性、前瞻性、非干预性研究