The observation period will last for up to 24 weeks, with Day 1 defined as the start date of Xolair treatment. It should be noted that, because the duration of Xolair treatment depends on the pollen dispersal situation and other factors, patients who complete or discontinue Xolair treatment before the visit at 24 weeks after the start of treatment will be followed up until the date of last dose of Xolair + 30 days, and the results will be recorded in the CRF.
This is a multicenter, uncontrolled, open-label, special drug use study to investigate the safety and efficacy of Xolair by collecting data in its clinical setting in patients with severe to most severe seasonal allergic rhinitis aged ≥ 12 years and < 18 years whose symptoms were inadequately controlled despite to conventional therapies and used Xolair.