Is loss of taste overestimated among COVID-19 patients?

Jeremy Booth, Dental Tribune International

Thu. 20. January 2022

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TRIESTE, Italy: The majority of COVID-19 patients self-report olfactory and gustatory disfunction, making these among the most common symptoms of the disease and the most common to affect the oral cavity. Researchers in Italy, however, have found that the prevalence of hypogeusia three months after the onset of symptoms may be significantly lower than self-reporting indicates.

In a cross-sectional study, researchers from University of Trieste assessed 105 COVID-19 survivors, of whom all had self-reported an impaired sense of taste and almost all (94.3%) olfactory impairment owing to COVID-19 infection. The vast majority (98.1%) of the patients had recovered from mildly symptomatic disease and had had no evidence of pneumonia. The researchers conducted psychophysical and psychological evaluations on the participants and found that hypogeusia could be confirmed in less than half (41.9%) of them. This figure fell to 28.6% after results were adjusted for participants’ age.

According to the researchers, self-reported hypogeusia can be a consequence of olfactory dysfunction. They stated: “[Indeed], our study found that even when specifically asked about basic tastes, more than half of patients self-reporting an altered taste perception exhibited a normal gustatory function, while most of them had an olfactory impairment.”

The researchers wrote: “[This] psychophysical study uncovers overestimation of self-reported taste impairment and supports the use of validated psychophysical tests to estimate the burden of chemosensory dysfunction in people with long-term COVID-19.”

The researchers said that, although the number of confirmed cases of hypogeusia may be lower than self-reporting indicates, the condition has thus far been largely overlooked. “While olfactory training may help the former group, additional strategies may be needed for those with gustatory impairment,” they wrote.

The study, titled “Comprehensive chemosensory psychophysical evaluation of self-reported gustatory dysfunction in patients with long-term COVID-19: A cross-sectional study”, was published online on 6 January 2022 in JAMA Otolaryngology—Head and Neck Surgery, ahead of inclusion in an issue.