What is the evidence for anosmia (loss of sense of smell) as a clinical feature of COVID-19? – a lay summary
In recent media stories some COVID-19 patients have reported that they seemed to lose some or all of their sense of smell. This review looked into whether this could be an actual clinical feature linked to COVID-19.
Some medical terms:
Anosmia is a total loss of the sensation of smell.
Hyposmia is a partial loss of the sensation of smell.
- The team found that the evidence from published literature linking an altered sense of smell with COVID-19 is limited and inconclusive. There were some reports from professional bodies of experts dealing with sensory conditions, but these were anecdotal.
- What is more, it has not been mentioned as a symptom in any of the existing 56 peer-reviewed studies that reported symptoms of patients with confirmed cases of COVID-19.
- The fact that the symptom has not been mentioned in research does not mean it does not exist – it would be simply because patients were not asked about it, nor thought to mention it. Perhaps it is a phenomenon only found in mild cases – the vast majority of patients involved in the research have been hospitalized.
- The emerging anecdotal clinical reports suggest that this feature should be investigated further. Doctors could make a point of asking patients about any changes to their sense of smell when they assess patients with suspected COVID-19.
Mandy Payne, 7 April 2020
This is a lay summary of a report repared for the Oxford COVID-19 Evidence Service of the Oxford Centre for Evidence Based Medicine, Nuffield Department of Primary Care Health Sciences, University of Oxford by James O’Donovan, Sarah Tanveer, Nicholas Jones, Claire Hopkins, Brent A Senior, Sarah K Wise, Jon Brassey and Trisha Greenhalgh, and posted on 23rd March 2020.
Disclaimer: the article has not been peer-reviewed; it should not replace individual clinical judgement and the sources cited in the original report should be checked. The views expressed in this commentary represent an interpretation by HealthWatch and do not necessarily represent those of Oxford CEBM, the NHS, the NIHR, or the Department of Health and Social Care. The views are not a substitute for professional medical advice.