Post-Covid-19 Patients Follow-up Study (COVID-19)

May 4, 2026 updated by: Per Ole Iversen, MD, University of Oslo

Occurrence and Clinical Management of Chemosensory, Trigeminal, and Salivary Dysfunctions in Post-COVID-19 Patients

Taste, smell, trigeminal and salivary function is impacted in post-COVID-19 patients

Study Overview

Study Type

Interventional

Enrollment (Actual)

176

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 Locations

    • Oslo
      • Oslo, Oslo, Norway, 0455
        • University of Oslo

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

Yes

Description

Inclusion Criteria:

-COVID-19 diagnosis

Exclusion Criteria:

-Not COVID-19 diagnosis

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: Screening
  • Allocation: N/A
  • Interventional Model: Sequential Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: Parosmia
Smell training

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Smell
Time Frame: two years
Olfactory (smell) function will be evaluated using the Twelve felt-tip Sniffin' Sticks test (Burghart Messtechnik GmbH, Holm, Germany). Participants are categorized into anosmic (score 0-6, no smell), hyposmic (score 7-10, reduced smell), and normosmic (score 11-12, normal smell), according to normative classification.
two years

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Taste
Time Frame: 2 years
Gustatory (taste) function is assessed using Taste Strips impregnated with solutions of four different taste qualities (sweet, sour, salty, and bitter) in four different concentrations (Burghart Messtechnik GmbH, Holm, Germany). Participants are classified into ageusic (score 0, no taste), hypogeusic (score 1-8, reduced taste) and normogeusic (score 9-16, normal taste) using a normative classification. Participants are considered to have a specific ageusia if they are unable to detect all four different concentrations of a particular tastant.
2 years
Dry mouth
Time Frame: 2 years
Xerostomia (oral dryness) iss categorized according to participants' self-reported perception as either no dry mouth (score 0), or dry mouth (score 1). Participants are asked whether the symptoms of xerostomia started before or after COVID-19 infection and are asked open-ended questions where they could describe their experience of oral dryness. Finally, they are asked to report whether there are food items that they had to refrain from eating because of parosmia, dysgeusia, dysesthesia or xerostomia.
2 years
Dysesthesia
Time Frame: 2 years
Dysesthesia (oral burning sensation) iss categorized as either no dysesthesia (score 0), or dysesthesia (score 1). Participants report how often they experienced dysesthesia (constantly, daily, sometimes, periodically, during meals, in between meals), asked to describe where in the mouth they experienced dysesthesia (whole tongue, anterior tongue, lips, palate, buccal mucosa, other), and identify food items that enhanced the dysesthesia (spicy, sweet, sour, salty, bitter).
2 years

Collaborators and Investigators

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

Investigators

  • Principal Investigator: Per Ole Iversen, PhD, Per Ole Iversen

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 (Actual)

April 1, 2021

Primary Completion (Actual)

April 25, 2023

Study Completion (Actual)

April 25, 2023

Study Registration Dates

First Submitted

April 27, 2026

First Submitted That Met QC Criteria

May 4, 2026

First Posted (Actual)

May 6, 2026

Study Record Updates

Last Update Posted (Actual)

May 6, 2026

Last Update Submitted That Met QC Criteria

May 4, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

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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