Study on Olfactory Training for Adults with Olfactory Dysfunction in Hong Kong Using Aromatic Substances Delivered by Portable Diffuser Randomized Controlled Trial for Treatment Effectiveness

What this Trial Is About

Researchers are studying the effects of olfactory training for patients with sensorineural olfactory dysfunction, such as those caused by infections, head injuries, or neurological diseases. This study aims to evaluate the treatment using aromatic substances delivered through a portable diffuser, building on previous findings in COVID-19 related smell loss. It focuses on the Hong Kong population and seeks to understand the impact of this training on patients with non-COVID-19 related olfactory issues. Participants will be randomly assigned to one of two groups the treatment group receives olfactory training using four aromatic substances Citrus limon, Eucalyptus radiata, Pelargonium graveolens, Juniperus virginiana delivered via a diffuser, while the control group receives the same diffuser with normal saline instead of essential oils. Both groups will follow the same routine of 20 seconds per substance, repeated three times daily for three months. The study is double-blinded to keep both patients and doctors unaware of group assignments. During the study, participants will undergo smell assessments using the University of Pennsylvania Smell Identification Test UPSIT and Butanol Threshold Test BTT. Quality of life will be measured with the Sino-Nasal Outcome Test SNOT-22, and subjective smell and taste perceptions will be recorded using a Visual Analogue Scale VAS. The primary outcomes measured after three months include changes in olfactory threshold, identification scores, quality of life, and taste and smell abilities. The study will run from July 2022 until June 2024 for patient recruitment, with follow-up assessments accordingly.

Olfactory Training on Smell Dysfunction Patients in HK