Photo Credit: Elisaveta Ivanova
The following is a summary of “Determinants of Persistence and Recovery of Chronic COVID19 Chemosensory Dysfunction,” published in the September 2024 issue of Allergy and Immunology by Minichetti et al.
Chemosensory dysfunction (CSD) following COVID-19 affects 2-4% of patients, equating to up to 4 million individuals in the US, with symptoms persisting beyond six months in some cases. Understanding the factors influencing recovery and persistence is crucial for developing targeted interventions. This study aimed to identify recovery predictors and evaluate the CSD quality in registry subjects who reported ongoing smell and taste dysfunction after COVID-19. Researchers analyzed data from 408 participants with persistent CSD across four major pandemic waves who completed questionnaires between 2021 and 2023. These assessments included demographics, sinonasal symptoms, and self-reported recovery status.
Additionally, objective measures of smell (University of Pennsylvania Smell Identification Test, UPSIT) and taste (Brief Smell and Taste Test, BWETT) were conducted on a subset of 108 participants. The results indicated an average symptom duration of 24±5 months in the chronic CSD cohort, with 70% of those infected in 2020 still experiencing symptoms. Early pandemic cohorts predominantly reported phantosmia and dysgeusia, while later, participants experienced disrupted scent and flavor discrimination and fluctuating chemosensory function.
Despite a low prevalence of subjective sinonasal symptoms, participants frequently reported sleep disturbances and mood disorders. Notably, the presence of cigarette phantom smells was associated with persistent CSD, whereas self-reported environmental allergies predicted recovery; specifically, dust mite allergies were inversely related to cigarette phantom smells. Although no treatment effectively resolved CSD, nasal steroids were reported as beneficial by those who recovered. Objective tests revealed significantly reduced smell and taste function in patients with chronic CSD compared to controls. In conclusion, chronic COVID-19-related CSD remains resistant to conventional anti-inflammatory treatments. Recovery is more likely in individuals with pre-existing environmental allergies and hypertension, while persistence is predicted by cigarette smoke phantosmia.
Source: sciencedirect.com/science/article/pii/S0091674924009138
