Triggers for Post-Viral Parosmia (ParosmiaQ)

Triggers for Post-Viral Parosmia After COVID-19 and Non-COVID-19 Infections

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.

Study Overview

• Status: Completed
• Conditions: Parosmia; Smell Disorder

Detailed Description

The questionnaire will be sent out to those reporting early stages of parosmia as a result of post-viral infection, including post-COVID-19 infection. The questionnaire will record demographic data and ask about COVID-19 status, COVID-19 diagnosis and results of COVID-19 tests. It will ask about loss of smell, taste and chemesthesis (irritation from the heat of spices) and it will ask about the sequence of events leading to parosmia. Up to 15 everyday items will be rated for aroma description, intensity and valence. Participants will be asked to list other distorted foods, and also smells that returned undistorted. The questionnaire will be fully anonymous (unlinked anonymous) and voluntary. The questionnaire will be designed, distributed and data collected using the secure platform provided by Compusense.

• Study Type: Observational
• Enrollment (Actual): 943

Contacts and Locations

Study Locations

• United Kingdom
  • Reading, United Kingdom, RG6 6AP
    • University of Reading

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Study population will be drawn from those currently suffering from parosmia only. Participants will initially be recruited from the AbScent membership which has a high proportion of UK and US members, but it will be rolled out internationally via ENT consultants.

Description

Inclusion Criteria:

• Individuals should be currently experiencing parosmia

Exclusion Criteria:

• Individuals below 18 years old will be excluded from the study

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Questionnaire	Outcomes from the questionnaire will be: List of major trigger foods for anosmia. Typical descriptions for smell distortions. Severity of parosmia. Patterns of anosmia/parosmia symptoms in post-viral infections including Covid-19.	20 minutes

Collaborators and Investigators

• Sponsor: University of Reading
• Collaborators: University College London Hospitals; University of London; AbScent
• Investigators: Principal Investigator: Jane K Parker, PhD, University of Reading

Publications and helpful links

Helpful Links

• Support and advice for those with smell disorders

Study record dates

Study Major Dates

• Study Start (Actual): November 3, 2020
• Primary Completion (Actual): July 31, 2021
• Study Completion (Actual): February 3, 2023

Study Registration Dates

• First Submitted: April 26, 2021
• First Submitted That Met QC Criteria: April 26, 2021
• First Posted (Actual): May 3, 2021

Study Record Updates

• Last Update Posted (Actual): May 9, 2023
• Last Update Submitted That Met QC Criteria: May 8, 2023
• Last Verified: May 1, 2023

More Information

Terms related to this study

• Keywords: COVID; Parosmia; Trigger foods
• Additional Relevant MeSH Terms: Nervous System Diseases; Neurologic Manifestations; Sensation Disorders; Olfaction Disorders
• Other Study ID Numbers: UoR SREC 29/2020

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: No personal identification data will be shared. The study is not under an obligation to share data, however it is possible that some of the individual (unlinked / non identifiable) data will be useful in a meta analysis and, hence sharing individual participant data (IPD) will be considered.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No