Persistent Dysosmia and Dysgeusia After COVID-19: Insights from AAAAI 2023 Data

Dante Minichetti

COVID-19 has presented a wide range of symptoms, from mild flu-like symptoms to severe respiratory distress. One of the most unique and common symptoms is the loss of smell and taste, known as dysosmia and dysgeusia. While these symptoms are also associated with other upper respiratory infections and chronic rhinosinusitis, the high frequency and severity of these symptoms in COVID-19 patients is unique.¹

A study featured at the American Academy of Allergy, Asthma & Immunology (AAAAI) 2023 Annual Meeting in San Antonio, TX, aimed to determine the characteristics of persistent dysosmia and dysgeusia after COVID-19 and define their mechanistic correlates. Findings suggested that COVID-19-induced sensory distortion is likely a multifactorial syndrome with distinct phenotypes.

An imprint of dysregulated macrophage and neutrophil mediated-immune response emerged from transcriptional data of persistent post-COVID-19 dysosmia. The distinct dysgeusia phenotypes are associated with eicosanoid dysregulation.

Understanding the COVID-19 Mechanisms

Further understanding can provide insights into the underlying mechanisms of COVID-19 and the potential long-term effects of the disease on sensory perception, Dante Minichetti, and a team of investigators from Brigham and Women’s Hospital, wrote.

The study included 542 patients with persistent olfactory or taste distortions after COVID-19, alongside 516 controls with normal smell and no history of COVID-19 at the time of enrollment. All participants underwent objective evaluations using validated assessment tools for smell (UPSIT) and taste (B-WETT) acuity. Cells for RNA sequencing and nasal fluid for mediator analysis were collected with self-administered Floqswabs and nasosorption strips.

Results demonstrated that both UPSIT and B-WETT were significantly reduced in the patients with persistent post-COVID-19 sensory disruption compared with controls. COVID-19-induced sensory distortions were clustered into 4 phenotypes: subjective dysosmia, objective dysosmia, dysgeusia, or combined dysosmia and dysgeusia.

Late-Breaking Data

RNA sequencing analysis revealed an increase of macrophage and neutrophil-associated transcriptional signatures in subjects with both dysosmia phenotypes but not in those with dysgeusia. Alternatively, the nasal hydroxyoctadecadienoic acid metabolites and the lipokine were elevated in patients with dysgeusia and negatively correlated with B-WETT.

The study also emphasized the importance of objective evaluations for smell and taste acuity in patients post-COVID-19 with persistent sensory distortion. These evaluations can help identify the specific phenotype and guide the appropriate management and treatment of these patients, the team wrote.

Overall, findings indicated dysosmia and dysgeusia are unique and common symptoms of COVID-19. The study provided insights into the characteristics and mechanistic correlates of persistent post-COVID-19 sensory distortion.

Additionally, the analysis suggested that COVID-19-induced sensory distortion is a multifactorial syndrome with distinct phenotypes and can have long-term effects on sensory perception. Objective evaluations for smell and taste acuity can guide the appropriate management and treatment of post-COVID-19 patients with persistent sensory distortion.

References:

1. Minichetti D, Boyd A, Hacker J, Wong C, Lemire E, Buchheit K, Lee S, Roditi R, Haber A, Laidlaw T. Macrophage and Neutrophil Dysregulation are Associated with Persistent COVID-19-induced Olfactory Dysfunction. J Allergy Clin Immunol. 2023 Feb;151(2):AB339. doi: 10.1016/j.jaci.2022.12.792. Epub 2023 Feb 3. PMCID: PMC9895812.