Chemosensory Dysfunction in Long-Term COVID-19 Assessed by Self-Reported and Direct Psychophysical Methods

Abstract

Chemosensory dysfunction is a frequent postacute sequela of COVID-19. Depending on the type of test used to measure it (self-report vs. direct test), the degree of chemosensory dysfunction in long-term COVID-19 has been found to be highly variable. In this manuscript, we report the cross-sectional data (first assessment) of a longitudinal study (6-month follow-up) examining smell, taste, and chemesthesis in participants affected by long-term COVID-19 (COVID+) and participants without COVID-19 (COVID−) by means of both self-reported and direct psychophysical methods. In total, 208 Italian participants (COVID+ n = 133; COVID− n = 75) completed the Smell and Taste Check developed by the Global Consortium for Chemosensory Research (GCCR), which includes self-reports on smell, taste, and chemesthetic abilities as well as direct intensity ratings of unstandardized smell, taste, and chemesthetic household items. Furthermore, all participants completed SCENTinel, a validated direct smell test. We found a positive association between the self-reported, unstandardized direct test and the validated direct test for smell, indicating moderate to large agreement across measures. Furthermore, the performance on SCENTinel was significantly associated with self-reported smell loss. A positive association between the self-reports and the intensity of household items was also retrieved for taste and chemesthesis. The time relative to COVID-19 onset (267.3 ± 113.9 days) did not modulate the chemosensory performance of self-reported abilities, intensity ratings, and SCENTinel. All in all, we confirm the impairment of three chemical senses (smell, taste, and chemesthesis) in an independent sample of Italian participants affected by long-term COVID-19 by using and comparing self-reported and direct psychophysical methods. We contribute to the discussion on best practices to monitor chemosensory dysfunction in individuals affected by long-term COVID-19.

Post-Viral Olfactory Loss: What We Learned from the SARS-CoV-2 Pandemic

“…The two contributions by Schambeck et al [65] and Albayay et al [66] analyze the prevalence of long-term olfactory disorders, confirming the important impact of this problem, as underlined by a study of the impact on the quality of life of persistent olfactory disorders by Vaira et al [67].…”

Smell, taste and chemesthesis disorders in patients with the SARS-CoV-2 Omicron variant in China

“…The questionnaire was adapted from an existing online questionnaires developed by the Global Consortium for Chemosensory Research (GCCR)(Parma et al 2020). The GCCR core questionnaire that implemented in 10 languages as of April 18, 2020 was used or adapted in many other research(Lee et al 2022; Cecchetto et al 2021; Albayay et al 2022). Data collected included the demographic, COVID-19-related characteristics and chemosensory situation before and during infection.…”

Smell, taste and chemesthesis disorders in patients with the SARS-CoV-2 during Omicron variant pandemic in China

“…The questionnaire was adapted from existing online questionnaires developed by the Global Consortium for Chemosensory Research (GCCR) [ 5 ]. The GCCR core questionnaire has been implemented in 10 languages as of April 18, 2020, and used or adapted in many other research studies [ 4 , 28 , 29 ]. Data collected included demographic information, COVID-19-related characteristics, and patient chemosensory situations, before and during infection.…”