NCT04868435: ParosmiaQ

Triggers for Post-Viral Parosmia

Completed Last updated 9 May 2023

What this trial tests

trial in Parosmia in 943 participants. Completed in 3 February 2023.

Timeline

3 November 2020

Primary endpoint
31 July 2021

3 February 2023

Quick facts

Lead sponsor	University of Reading
Status	Completed
Study type	OBSERVATIONAL
Enrollment	943
Start date	3 November 2020
Primary completion	31 July 2021
Estimated completion	3 February 2023
Sites	1 location across United Kingdom

Conditions studied

• Parosmia — all drugs for Parosmia →
• Smell Disorder — all drugs for Smell Disorder →

Sponsor

University of Reading

Who can join

18 and older, any sex, with Parosmia or Smell Disorder. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

Background: Many people lose their sense of smell after they have had a cold, flu or sinus infection. Recovery (if at all) generally starts with a "parosmia" phase which means every-day smells become distorted and over-poweringly objectionable, and this can lead to malnutrition and depression. We do not know much about how or why parosmia happens, but there are key foods common to those who suffer from parosmia which seem to trigger the distortion.

Parosmia and COVID-19 Loss of smell has recently been recognised as an official symptom of COVID-19, and we are starting to get reports of people who have recently had COVID-19 developing parosmia. The triggers seem to be similar to those of the common cold, flu or virus infections, but the journey between loss of smell and parosmia is different.

Hypotheses

1. Triggers of distortion will be the same for all parosmics.
2. There may be additional trigger foods in different cultures.

Questions

1. What are the trigger foods and beverages for parosmia?
2. Are there regional/cultural variations?
3. Does Covid-19 parosmia differ from "standard" post-viral parosmia?

The overall aim of the project is to understand the mechanisms involved in parosmia. The approach is to identify foods and everyday aromas associated with parosmia and to determine whether they are the same across different continents/cultures/ethnic backgrounds, and whether Covid-19 parosmia is any different to non-Covid-19 parosmia. The questionnaire will ask about Covid-19 status, ethnic background, smell loss and parosmia, and the changes that occurred between smell loss and parosmia. The participants will then answer questions on up to 15 everyday smells, some of which our preliminary evidence shows are common triggers, and others which are not. The questionnaire will be globally distributed, for example through current collaborations in the UK, US, Germany, Iran, China, Japan and Brazil. It will be completed by participants who are currently experiencing parosmia.

All participants will be asked to record any foods that they find distorted and provide a list of aromas which returned undistorted.

Publications & conference data

2 peer-reviewed publications reference this trial (live from Europe PMC):

1. Emerging Pattern of Post-COVID-19 Parosmia and Its Effect on Food Perception.
   Parker JK, Methven L, Pellegrino R, Smith BC, et al · · 2022 · cited 23× · PMID 35407054 · DOI 10.3390/foods11070967
2. SARS-Cov-2 Damage on the Nervous System and Mental Health.
   Boulkrane MS, Ilina V, Melchakov R, Arisov M, et al · · 2022 · cited 4× · PMID 34191699 · DOI 10.2174/1570159x19666210629151303