Modified Olfactory Training Is Effective in Treating Post–COVID-19 Parosmia

by Linda Kossoff •

How effective is modified olfactory training (MOT) for the treatment of COVID-19–induced parosmia?

BOTTOM LINE

MOT is an effective treatment modality for post–COVID-19 parosmia, with evidence of symptom improvement after six months.

BACKGROUND: Parosmia has been reported to develop after COVID-19 and may be a sign of recovery in olfactory function following anosmia. Classical olfactory training (COT) and MOT are reportedly the most effective treatment modalities in treating post-infectious olfactory dysfunction; however, no research exists on the treatment of post–COVID-19 parosmia.

STUDY DESIGN: Prospective cohort study.

SETTING: Department of Otolaryngology–Head and Neck Surgery, Biruni University School of Medicine, Istanbul, Turkey.

SYNOPSIS: Researchers recruited 75 patients with anosmia, hyposmia, and parosmia following COVID-19 infection who were referred to a single otorhinolaryngology clinic. Patients were separated into two age- and gender-matched groups. The treatment group of 38 parosmia patients received MOT; the control group of 37 parosmia patients received no rehabilitation therapy. Both groups’ TDI (threshold, discrimination, and identification) scores were compared at application and at end of month nine using the Sniffin’ Sticks Test. Although significant improvement was observed in both groups at months three, six, and nine, improvement in the treatment group was better. Moreover, extending treatment from six to nine months was effective in mitigating parosmia complaints and improving discrimination scores. Comparing MOT and COT, the extension of MOT from 12 to 24 weeks was more effective in improving olfactory function compared to COT. At the end of month nine of MOT, discrimination scores increased and parosmia complaints were significantly mitigated. While both groups improved, treatment group improvement was significantly better. The main limitation of this study was that group assignment choice was left to the patient’s preference.

CITATION: Altundag A, Yilmaz E, Kesimli MC. Modified olfactory training is an effective treatment method for COVID-19 induced parosmia. Laryngoscope. 2022;132:1433-1438. doi:10.1002/ lary.30101.