Inclusion Criteria:

• Moderate-to-severe asthma patients aged ≥ 14 years who met the criteria of the Asthma Group of the Chinese Thoracic Society (Guidelines for bronchial asthma prevention and management, 2020 edition)-moderate asthma was defined as those who could achieve complete control using grade 3 therapy, and severe asthma was defined as fully or incompletely controlled with grade 4 or 5 asthma medications.
• History of asthma exacerbations induced by allergen exposure , elevated total serum IgE and positive specific IgE test or positive skin prick test.
• Treatment with omalizumab.

Exclusion Criteria:

• Hypersensitivity to the active ingredient of omalizumab.
• Asthma exacerbation in the baseline.
• Combined with diseases that severely affect ventilation,such as bronchiectasis, lung cancer, allergic bronchopulmonary aspergillosis (ABPA), acute respiratory infections, chronic obstructive pulmonary disease (COPD),etc.
• Receiving other biologically targeted therapies (e.g., anti-interleukin (IL)-5 monoclonal antibody, anti-IL-4 monoclonal antibody, anti-IL-13 monoclonal antibody, anti-IL-5 receptor α (IL-5Rα) monoclonal antibody, etc.)