Persisting olfactory dysfunction improves in patients 6 months after COVID-19 disease

Background Smell disorders persist in about half of the patients with other symptoms of COVID-19 disease, but the exact duration of the symptoms is yet unknown. Especially, only a few studies used validated olfactory tests for this. Aims/Objectives The aim of this study was to investigate how many patients with olfactory function impairment, which was detected in a validated olfactory test 3 months after COVID-19 disease, showed improvement in olfactory function after 6 months. Methods About 26 patients with a PCR-confirmed, former COVID-19 disease, with an impaired olfactory function after three months, were included in the study. The olfactory function was evaluated with the sniffing sticks test, the taste function with taste sprays. Results Smelling function improved in all but one patient (96%). All measured subitems, i.e. olfactory threshold, identification and discrimination of odours significantly improved. In the whole mouth taste test all patients showed normal taste function. Conclusions and significance 6 months after COVID-19 disease, olfactory function improves in just about all patients. Long-term measurements must investigate whether complete regeneration of the olfactory function will occur in all patients.

Automated summary

The study aimed to investigate the improvement of olfactory function in patients with impaired olfactory function detected in a validated olfactory test 3 months after COVID-19 disease, and found that 96% of patients showed improvement in olfactory function after 6 months with all measured subitems significantly improved.