Scientists Find Key Reason Why Loss of Smell Occurs in Long COVID-19; Inflammatory Mechanism Could Also Help Explain Other Long COVID-19 Symptoms

The reason some people fail to recover their sense of smell after COVID-19 is linked to an ongoing immune assault on olfactory nerve cells and an associated decline in the number of those cells, a team of scientists led by Duke Health report. The finding, published online on December 21, 2022 in Science Translational Medicine, provides an important insight into a vexing problem that has plagued millions who have not fully recovered their sense of smell after COVID-19. While focusing on the loss of smell, the finding also sheds light on the possible underlying causes of other long COVID-19 symptoms--including generalized fatigue, shortness of breath, and brain fog--that might be triggered by similar biological mechanisms. The open-access article is titled “Persistent Post–COVID-19 Smell Loss Is Associated with Immune Cell Infiltration and Altered Gene Expression in Olfactory Epithelium.”