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Status unknownNCT04764981Updated Feb 21, 2021

Olfactory Training for Olfactory Dysfunction After Coronavirus Disease - 19 (COVID-19)

An interventional study of Essence oils in Covid19, SARS-CoV Infection and Olfactory Disorder, sponsored by Universidade do Estado do Pará. Status unknown at 1 site in Brazil. Open to participants aged 18 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2021-02-21.

Sponsored by Universidade do Estado do Pará · Not applicable, Interventional, and Treatment

The sponsor has not verified this record recently (last verified Feb 2021), so the status shown — last known as Enrolling by invitation — may be out of date.
Phase
Not applicable
Study type
Interventional
Enrollment
350
Allocation
Randomized
Ages
18 Years to 65 Years
Sex
All
01

Study summary

It is a randomized controlled clinical trial study that aims to follow a sample of individuals with persistent olfactory dysfunction post-COVID-19. The aim of this study is assess the clinical outcomes of olfactory training therapy in the treatment of persistent olfactory dysfunctions after COVID-19. The sample will consist of 350 participants, being 300 individuals with persistent olfactory dysfunction post-COVID-19 and 50 healthy individuals. Volunteers' will be separated in two experimental groups (1 and 2 ) and a control group. All participants will be submitted to clinical evaluation that include the Connecticut Chemosensory Clinical Research Test (CCCRT), an olfactory test to diagnose anosmia and hyposmia, and two skull Magnetic Resonance imaging (MRI). Only participants of Experimental group 1 will be submitted to an olfactory training with essences oils. Experimental group 2 will only receive a clinical follow-up after three months and control group will be only submitted to neurological exam, olfactory test, MRI imaging and test their ability to discriminate the essence oils used in olfactory training. As a result, is expected a better understanding of the characteristics of olfactory dysfunction caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) virus infection, as well as the effectiveness and viability of using Olfactory Training as a therapeutic alternative.

02

Conditions studied

  • Covid19
  • SARS-CoV Infection
  • Olfactory Disorder
  • Anosmia
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In context

COVID-19

7,640 studies on the registry are indexed under COVID-19; 488 are open to participants now.

This study's planned enrollment of 350 is above the median of 100 across 4,099 interventional studies indexed under COVID-19.

Browse COVID-19 studies →

Lead sponsor

Universidade do Estado do Pará is the lead sponsor of 6 studies on the registry; 4 are open to participants now.

Counted across the registry records on this site, refreshed daily.

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Who can participate

Ages eligible
18 Years to 65 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  • Confirmed diagnosis of COVID-19 by Real Time Polymerase chain-reaction for SARS-CoV-2 or serological tests for SARS-CoV-2 antigens.\
  • Olfactory dysfunction confirmed by Connecticut Chemosensory Clinical Research Test (CCCRC-T).

Exclusion criteria

Exclusion Criteria:

  • Smokers
  • Individuals with diagnosed rhinitis
  • Individuals with diagnosed Neurological diseases
  • Individuals submitted to brain surgery
  • Previous historic of hyposmia and/ or anosmia
  • Pregnancy
  • Allergy to any of the substances present in the olfactory test kit
  • Individuals who are undergoing another treatment for olfactory dysfunction
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Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Double (Participant, Outcomes assessor)
Enrollment
350 participants (estimated)

Study arms

  • Experimental
    Experimental Group 1: Essences Oils

    The individuals of this group are 150 individuals with olfactory disorder related to COVID-19 that will be submitted to clinical exams, olfactory test and MRI imaging, after that, participants will undergo an olfactory training with essences oils. Each participant in this group will receive a kit with four 30 ml bottles, each containing a circular piece of watercolor paper soaked in one of the four essences oils (rose, eucalyptus, lemon and cloves) used in olfactory training, a manual to make the olfactory training at home and a self-assessment diary which should be filled weekly. Each participant of this group will use the training kit for three months, the olfactory training consists of inhaling each of the substances for 30 seconds, with an interval of 30 seconds between them, twice a day, upon waking up and before bed, the participants will be reassessed with CCCRT after each month of training. The results of this group will be compared with the other groups.

    Other: Essence oils

  • No intervention
    Experimental Group 2: Clinical follow-up

    The individuals of this group are 150 individuals with olfactory disorder related to COVID-19. that will be submitted to clinical exams, olfactory test and MRI imaging, after three months they will be reassessed.

  • No intervention
    Control Group

    The individuals of this group are 50 healthy individuals, without previous COVID-19 infection, that will be submitted to clinical exams, olfactory test, MRI imaging and the participants will be tested for the ability to identification of the essence oils utilized by Experimental group 1.

Interventions

  • OtherEssence oils

    Consists in olfactory training using essence oils

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What researchers measure

Primary outcomes

  1. To Assess the effectiveness of olfactory training therapy in the treatment of persistent olfactory dysfunctions after COVID-19

    The individuals of Experimental group 1 will be submitted to a olfactory training with essence oils, the participants will be reassessed with Olfactory test CCCRT monthly and this results will be compared with the reassessment results of the Experimental group 2 (no intervention group). The results of CCCRT of these two groups will be compared with Control group. The CCCRT olfactory test consists of n-butanol smell threshold test and smell identification test. Olfactory function score will be assessed (0: worst score; 7: best score).

    Time frame: 4 years

Secondary outcomes

  1. To Investigate by means of skull nuclear magnetic resonance (MRI) exams for possible neural correlates of olfactory dysfunctions present in post-COVID-19 patients

    MRI imaging of olfactory bulb will be assessed in the individuals of this study, for better understanding of possible lesions at neural sites

    Time frame: 4 years

  2. To Measure by means of a standardized olfactory test the olfactory dysfunctions present in post-COVID-19 patients

    CCCRT will be used to classify individuals as having normosmia, hyposmia or anosmia

    Time frame: 4 years

  3. Propose an olfactory training protocol appropriate to the demands of patients with post-COVID-19 olfactory dysfunction and in accordance with the reality of Brazilian public health services

    The olfactory training using essence oils will be tested in this study as a low cost alternative for therapeutics

    Time frame: 4 years

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Study locations

1 site
  • Unidade de Ensino E Assistência Em Fisioterapia E Terapia Ocupacional
    Belém, PA 66095-661, Brazil
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Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Feb 21, 2021, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT04764981
Lead sponsor
Universidade do Estado do Pará
Responsible party
ALNA CAROLINA MENDES PARANHOS (Professor, Universidade do Estado do Pará) — Principal investigator
First posted
Feb 21, 2021
Start date
May 2021 (estimated)
Primary completion
May 2022 (estimated)
Completion
May 1, 2024 (estimated)
Last update
Feb 21, 2021

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is status unknown, as verified in Feb 2021. You cannot join it, but the record below documents what was studied.

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