The Effectiveness of Steroid Nasal Drops in the Olfactory Cleft Combined With Olfactory Training for Patients With PIOD (PIOD)

February 2, 2026 updated by: Dawei Wu, Peking University Third Hospital

Randomized Controlled Study on the Effectiveness of Steroid Nasal Drops in the Olfactory Cleft Combined With Olfactory Training for Patients With Post-infectious Olfactory Dysfunction

This study aims to evaluate the effectiveness of hormone nasal drops in the olfactory cleft combined with olfactory training for treating postinfectious olfactory dysfunction (PIOD). The main questions this clinical trial seeks to answer are:

Can the combination of hormone nasal drops and olfactory training improve smell function better than olfactory training alone in PIOD patients? How does this combined treatment work?

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Post-infectious olfactory dysfunction (PIOD) is a prevalent condition, particularly following viral upper respiratory infections such as COVID-19, and significantly impacts patients' quality of life. Current treatments primarily rely on olfactory training, but its effectiveness varies, with improvement rates ranging between 30% and 50%. Emerging evidence suggests that olfactory cleft obstruction and chronic inflammation play critical roles in PIOD pathogenesis, highlighting the potential benefits of targeted steroid therapy to address these underlying mechanisms.

In this study, the investigators planned to recruit 100 patients and divided them into two groups for combined therapy with steroid drops or placebo drops alongside olfactory training, and validate the effectiveness of the combined therapy based on the comparison of the outcomes of the two groups.

Study Type

Interventional

Enrollment (Estimated)

100

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • China
    • Beijing Municipality
      • Beijing, Beijing Municipality, China, 100191

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Prospective enrollment of otolaryngology clinic patients aged 18-65 years with olfactory dysfunction. Diagnosis of post-infectious olfactory dysfunction (PIOD) will be based on the PPOD 2023 criteria. Participants must demonstrate olfactory impairment via Sniffin' Sticks testing, with TDI scores (sum of Threshold, Discrimination, and Identification) meeting: (1) Hyposmia: 16 < TDI < 30.75; (2) Anosmia: TDI ≤ 15.
  2. Willingness to participate and signed informed consent.

Exclusion Criteria:

  1. Use of systemic corticosteroids within 4 weeks or intranasal steroids within 2 weeks prior to enrollment.
  2. Severe nasal septum deviation, nasal tumors, acute upper respiratory infections, or uncontrolled allergic rhinitis.
  3. History of functional endoscopic sinus surgery or other nasal procedures within 12 months.
  4. Severe cardiovascular disease, hepatic/renal insufficiency, uncontrolled diabetes, or immune system disorders.
  5. Current or planned pregnancy.
  6. Investigator-determined inability to comply with study requirements (e.g., memory/behavioral disorders, depression, heavy alcohol use, prior non-compliance).

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Hormone Nasal Drops Combined with Olfactory Training Group

Olfactory Cleft Steroid Nasal Drops: Patients will be instructed to assume the Mygind position. Five drops of budesonide suspension (2ml:1mg) will be instilled into each nostril to facilitate delivery to the olfactory cleft. This position will be maintained for 5 minutes, after which patients should expectorate any residual medication. The treatment regimen will follow a tapered schedule: twice daily during the first treatment month, reduced to once daily in the second month, and further reduced to every other day in the third month.

Olfactory Training: Participants will perform olfactory training using a modified training device programmed with four distinct odorants (rose, peppermint, tea tree, and clove). Each odorant will be sniffed for 10 seconds per nostril, with 10-second intervals between odorants. Each training session lasts 5 minutes and is conducted twice daily, before breakfast and at bedtime, for a duration of 3 months.
Combination product: Steroid nasal drops combined with olfactory training
The intervention consists of two components: steroid nasal drops and modified olfactory training.
Placebo Comparator: Placebo Nasal Drops Combined with Olfactory Training Group
The placebo group will receive normal saline nasal drops, with all other procedures identical to those in the intervention group.
Combination product: Placebo nasal drops combined with olfactory training
The intervention consists of two components: normal saline nasal drops and modified olfactory training.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
The Sniffin' Sticks test
Time Frame: Baseline, 1 week, 4 weeks, 8 weeks, and 12 weeks after the initiation of treatment.
A clinically significant olfactory improvement as measured by Sniffin' Sticks threshold, discrimination, and identification(TDI)
Baseline, 1 week, 4 weeks, 8 weeks, and 12 weeks after the initiation of treatment.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Questionnaire of Olfactory Disorders - Negative Statements (QOD-NS)
Time Frame: Baseline, 2 weeks, 4 weeks, 8 weeks, and 12 weeks after the initiation of treatment.
The QOD-NS includes 17 negative statements, each graded from 0 (disagree) to 3 (agree) for a maximum score of 51. Higher QOD-NS scores reflect worse QoL.
Baseline, 2 weeks, 4 weeks, 8 weeks, and 12 weeks after the initiation of treatment.
Olfactory-Visual Analogue Scale (VAS)
Time Frame: Baseline, 2 weeks, 4 weeks, 8 weeks, and 12 weeks after the initiation of treatment.
Subjects rate the impact of smell loss on their mood, ability to enjoy food, social interactions, safety, personal hygiene, sex life, ability to cook food, appetite and change in weight from 0 (no impact) to 10 (most impact) for a maximum score of 90. Higher olfactory-VAS scores reflect more severe impacts on daily life.
Baseline, 2 weeks, 4 weeks, 8 weeks, and 12 weeks after the initiation of treatment.
CT Evaluation of Olfactory Cleft Blockage
Time Frame: Baseline and 12 weeks after the initiation of treatment.

The olfactory cleft was divided into anterior and posterior, divided by the anterior end of the superior turbinate. The anterior and posterior olfactory cleft opacifications were graded separately on a scale of 0-4 by the ratio of the opacified area to the whole area of the olfactory cleft, with 0 (no opacification),

1 (25%), 2 (25%-50%), 3 (50%-75%), and 4 (>75%). The olfactory cleft CT score, calculated as the sum of the anterior and posterior olfactory cleft scores, ranged from 1 to 8 (Kim DW, Kim JY, Jeon SY. The status of the olfactory cleft may predict postoperative olfactory function in chronic rhinosinusitis with nasal polyposis. Am J Rhinol Allergy. 2011;25(2):e90-4.).
Baseline and 12 weeks after the initiation of treatment.
Inflammatory Marker Levels in Olfactory Mucosa
Time Frame: Baseline and 12 weeks after the initiation of treatment.
Analysis of inflammatory cytokines （IL-4、IL-5、IL-13、IL-25、IL-33 and TSLP）via ELISA and single-cell sequencing from olfactory mucosal brush samples.
Baseline and 12 weeks after the initiation of treatment.
Plasma Cortisol Levels
Time Frame: Baseline and 12 weeks after the initiation of treatment.
Measurement of systemic cortisol concentrations through venous blood sampling
Baseline and 12 weeks after the initiation of treatment.
Adverse Event
Time Frame: 2 weeks, and 4 weeks, 8 weeks, and 12 weeks after the initiation of treatment.
Documentation of local (nasal irritation, epistaxis) and systemic steroid-related adverse events using standardized case report forms during all follow-up visits.
2 weeks, and 4 weeks, 8 weeks, and 12 weeks after the initiation of treatment.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Peking University Third Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

March 1, 2026

Primary Completion (Estimated)

December 31, 2028

Study Completion (Estimated)

December 31, 2028

Study Registration Dates

First Submitted

January 24, 2026

First Submitted That Met QC Criteria

February 2, 2026

First Posted (Actual)

February 4, 2026

Study Record Updates

Last Update Posted (Actual)

February 4, 2026

Last Update Submitted That Met QC Criteria

February 2, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 9059106

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

We will decide whether to share the individual participant data after the study.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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