- Half of first-wave Covid cases may have lasting harm to sense of smell
Nearly half of those who became ill with Covid in the first wave of infections may have long-term and even permanent changes to their sense of smell, according to preliminary research from Sweden.
A sudden loss of smell, or an impaired or distorted perception of odours, emerged as an unusual symptom of Covid early on in the pandemic. While many people swiftly recovered, others found that their sense of smell never quite returned to normal.
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To find out how common the impairments might be, scientists at the Karolinska Institute in Stockholm ran comprehensive tests on 100 individuals who caught Covid in the first wave of infections that swept through Sweden in spring 2020.
Their early findings show that 18 months after recovering from Covid, very few people – only 4% – had lost their sense of smell entirely, but a third had a reduced ability to detect odours, and nearly half complained of parosmia, where the sense of smell is distorted. Most of those with a reduced sense of smell were unaware of it before they joined the study.