The Effect of Olfactory Training in Patients With COVID-19 Induced Olfactory Dysfunction (SMELLT2022)

Ditte Gertz Mogensen

Status

Enrolling

Conditions

COVID-19

Treatments

Other: Olfactory training with essential oils

Other: Olfactory training with fragrance-free oils

Study type

Interventional

Funder types

Other

Identifiers

NCT05539560

2022-ENT-1-olfactory

Details and patient eligibility

About

Aim: The aim is to investigate the effect of olfactory training with essential oils versus olfactory training with placebo-oils in patients with COVID-19 induced olfactory dysfunction

Study design: The study is a placebo-controlled randomized clinical trial with an intervention group and a control group. The intervention group receive four essential oils with scents of orange, lavender, clove, and peppermint. Patients in the control group receive a fragrance kit, consisting of the same containers, but with fragrance-free oils added. Both groups are instructed to smell each of the four oils for 30 seconds in the morning and evening, over a three-month intervention period. Patients are given a diary in which to record their olfactory training. The nurse or medical student instructing the patients in the training and performing the smell and taste tests is blinded.

Study population: Patients referred to the Unit for Sense of Taste and Smell in the Department of Otorhinolaryngology Head & Neck and Audiology at Rigshospitalet.

Inclusion criteria:

Impaired sense of taste and smell following COVID-19 > 3 months
Hyposmia (16.25-30.5) or anosmia (<16) assessed by Sniffin' Sticks Olfactory Test for Threshold, Discrimination and Identification (TDI) performed in the Unit for Sense of Taste and Smell with or without parosmia based on medical history
> 18 years of age

Exclusion criteria:

Cause of hyposmia, anosmia or parosmia other than COVID-19
Does not read or speak Danish
Lack of compliance to perform daily olfactory training

Procedures:

TDI-test: To assess patients' sense of smell, the TDI-test with Sniffin' Sticks is used, which is a validated tool with normative data.

Questionnaires:

'Taste and Smell Tool for Evaluation' is used to investigate quality of life related to impaired sense of taste and smell.

Enrollment

65 estimated patients

Sex

All

Ages

18+ years old

Volunteers

No Healthy Volunteers

Inclusion criteria

Olfactory dysfunction caused by COVID-19
Hyposmia (16.25-30.5) or anosmia (<16) with or without parosmia assessed by TDI test with Sniffin Sticks performed in the Unit for Sense of Taste and Smell
> 18 years of age

Exclusion criteria