Clinical Research Directory

Inclusion Criteria: 1. Men and women aged 18-65 years old. 2. Diagnosis of CRS according to the EPOS 2020, with olfactory dysfunction lasting ≥ 12 weeks. 3. Evidence of eosinophilic/type 2 inflammatory CRS, defined by at least one of the following: JESREC score ≥11, peripheral blood eosinophils ≥5%, absolute blood eosinophil count ≥ 0.25 × 10⁹/L. 4. Confirmation of OD via Sniffin' Sticks test: TDI score \<30.75 (hyposmia: 16 \< TDI \< 30.75; anosmia: TDI ≤ 16). 5. Sinus CT scan confirming olfactory cleft abnormalities (e.g., mucosal thickening, polypoid changes, obstruction). 6. Willingness to participate in this study and sign the informed consent form (ICF). Exclusion Criteria: 1. Patients who have used systemic corticosteroids within the past 4 weeks or who have used intranasal corticosteroids within the past 2 weeks, or biologic therapy targeting type 2 inflammation within 6 months before enrolment. 2. Patients with severe deviation of the nasal septum, nasal tumors, acute upper respiratory tract infection or uncontrolled allergic rhinitis. 3. Patients with severe cardiovascular diseases, liver or kidney dysfunction, uncontrolled diabetes, or immune system disorders or other systemic disease that may interfere with study participation or safety. 4. Patients with current pregnancy or plan to become pregnant during the study period. 5. Patients with known hypersensitivity or contraindication to budesonide or any study medication component. 6. Patients who are unable to complete the study or are unable to comply with the requirements of the study (including inability to tolerate olfactory function testing and treatment, memory or behavioral abnormalities, depression, smoking, heavy alcohol use or prior non-compliance, specifically early withdrawal from a study).