In Response to Isolated Anosmia and Ageusia in COVID‐19 With Spontaneous Recovery

Dear Editor:

We really appreciated the interest shown in our communication1 by Dr. Ish and colleagues.2 Our communication was submitted to The Laryngoscope on March 16, 2020, during the very first days of the Italian severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) outbreak. Our need was to warn the scientific community as soon as possible about the high frequency of chemosensitive symptoms in patients with coronavirus disease 2019 (COVID‐19) in Italy. For this reason, it was not possible to collect and report more anamnestic and prognostic details, but we think our communication has succeeded in its aim of informing colleagues throughout the world.

We would like to thank Dr. Ish and colleagues for reporting the result of their anamnestic analysis of 170 COVID‐19 patients. The frequency of chemosensitive disorders was very low (4.1%) and similar to that reported by Mao et al.3 in China. Obviously, we agree with colleagues that with such a low frequency the chemosensitive disorders cannot be considered as highly indicative and specific of SARS‐CoV‐2 infection. But in Europe and the United States, several authors agree on attributing to these symptoms a much higher frequency, around 75%.4, 5 The reasons for this difference are still far from being clarified but could be related to a different level of expression of angiotensin‐converting enzyme 2 receptors in the first air‐digestive pathways between different ethnic groups.6, 7

We do not agree with the authors that clinical evaluation is not indicated at this time. It is certainly logistically difficult, but only objective data can provide precise information on the frequency and functional recovery rate. On the basis of our evaluations with psychophysical tests,8, 9, 10 chemosensitive disorders tend to gradual functional recovery in the first 14 days. However, especially for smell, this recovery is often partial, and about 25% of patients have long‐lasting anosmia or severe hyposmia. The risk of long‐term morbidity could justify the implementation of specific treatments in this cohort of patients, starting from day 14 onward, which also coincides with the end of the high‐risk period for respiratory deterioration.10