This was 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.

The observation period lasted 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 completed or discontinued Xolair treatment before the visit at 24 weeks after the start of treatment were followed up until the date of last dose of Xolair + 30 days, and the results were recorded in the CRF.

Inclusion Criteria:

1. Patients who used Xolair in accordance with the instructions of package insert
2. Patients aged ≥ 12 years and < 18 years at the start of Xolair
3. Patients who used Xolair for the following indication:

Indication: seasonal allergic rhinitis (only patients with severe to most severe symptoms whose symptoms were inadequately controlled despite to conventional therapies) 4. Patients having provided written consent to participate in this study before the start of Xolair in the relevant pollen season, in person and from their legally acceptable representative (legal representative)

Exclusion Criteria:

1. Patients with a history of hypersensitivity to any of the Xolair ingredients

The study population was patients with seasonal allergic rhinitis.