Olfactory disturbances as presenting manifestation among Egyptian patients with COVID-19: Possible role of zinc

Abstract Background: COVID-19 is a severe acute respiratory syndrome caused by coronavirus 2 (SARS-CoV-2). Deficiency of zinc has been supposed to contribute to loss of smell, and taste in COVID-19 patients. Our study aimed to assess the serum zinc levels among patients with COVID-19 of various severities, with and without olfaction dysfunction. Also, to evaluate the effect of zinc therapy in recovery of smell dysfunction among such patients.Methods: This study included 134 patients; real-time reverse transcription- polymerase chain reaction (rRT-PCR) proved SARS-CoV-2. Serum zinc levels were measured for all infected patients. One hundred and five patients were detected to have anosmia and/ or hyposmia and who were categorized randomly into 2 groups, the first group included 49 patients received zinc therapy and a second group included 56 patients who did not receive zinc. Follow up of all patients for recovery duration of olfactory and gustatory symptoms and duration of complete recovery of COVID-19. Results: Olfactory dysfunction was reported in 105 patients (78.4%). Serum zinc levels weren't significantly differs between the patients' subgroups regarding disease severity or the presence or absence of olfactory and/or gustatory dysfunction (p˃0.05). The median duration of recovery of gustatory and/or olfactory function was significantly shorter among patients received zinc therapy than those who did not received zinc (p< 0.001), while the median duration of complete recovery from COVID-19 wasn't significantly differ among the two groups (p˃0.05).Conclusion: Although zinc status of COVID19 patients didn't exhibited a significant role in development of anosmia and/or hyposmia or disease severity, but zinc therapy may have a significant role in shortening the duration of smell recovery in those patients without affecting the total recovery duration from COVID-19.