GRASS (Grass MATA MPL Real-world Assessment Study)

At the physician's discretion and based on the current Summary of Product Characteristics (SmPC), study participation may be offered to patients who * are male and female patients * are 18 years of age or older * treated in accordance with the SmPC of Grassmuno® for IgE-mediated moderate to severe allergic rhinitis and/or rhinoconjunctivitis (without asthma or with well-controlled asthma) triggered by grass pollen. * Patients will only be enrolled in the study after the treatment decision has been made Exclusion Criteria: At the physician's discretion, the study should not be offered to the following patients: * Patients who are not sufficiently proficient in or do not adequately understand the German language, as this would prevent adequate comprehension of study-relevant documents. * In addition, patients should not be included if any of the contraindications listed in the current Summary of Product Characteristics (SmPC) are present.