INTRODUCTION
COVID-19
How Does The Virus Affect The Ability To Smell?
SARS-CoV-2, also known as Covid-19 and Coronavirus, has had a phenomenal impact on the world since its discovery in 2019. Research is continuing, we have many papers shared on our website repository and news stories on our news page.
Many scientists agree that SARS-CoV-2, like the earlier known SARS-CoV, uses the angiotensin-converting enzyme 2 (ACE2) receptor to gain entry to cells by binding with spike protein. This receptor is found on the support cells that along with olfactory neurons, make up the olfactory epithelium.
How Likely Is Recovery from Covid-19 Smell Loss?
In most people, recovery has been relatively fast which indicates that the virus does not always kill the olfactory neurons. Because sudden smell loss occurs early in the disease or without any other symptoms, a full understanding of the virus’ entry into cells in the olfactory sensory epithelium is particularly important for further understanding the infection.
Just like other post-infection smell loss, these support cells can regenerate and the olfactory epithelium can recover. Early research indicates that over 80% of people who lose their sense of smell from Covid-19 are achieving full recovery. Sometimes whilst recovery is taking place, the messages that go to the brain via the olfactory cells might not work like they should, causing smell messages to be misinterpreted, resulting in distortions of smell odours or smell hallucinations also known as parosmia and phantosmia.
Whilst recovery is most likely, the time frame for this can be incredibly variable. For some, smell training can help – see our SmellAbility resources for more guidance on how to do this.
What You Can Do To Help Your Recovery
Like any damage to the body, recovery takes time and care but there are many things you can do to help with this. Make sure you look after your health and pay attention to good nutrition. Whilst food might not be appetising and in the case of parosmia might also be very unpleasant, finding foods that you can tolerate is important.
- Download/print off our Learning Zone Information Sheet #1 Post Viral Olfactory Disorders
- Download/print off our Learning Zone Information Sheet #7 Coping with Parosmia/Phantosmia
- Keeping a diary recording what tastes you can detect and what causes parosmia to trigger can be helpful. An example of this is included on Information Sheet #7 Coping with Parosmia/Phantosmia
- Watch Ms Cath Rennie and Lizzie Bullock from Imperial College Hospitals explain more about Post Viral Smell Disorders including Covid-19
- Our Food for Thought section can give you ideas and help to continue to eat well.
- Nasal rinsing may also help – regular cleaning can help to remove general debris and be an aid to reduce inflammation.
- Whilst smell training isn’t a quick fix or an intervention that works for everyone, there has been scientific research undertaken that underpins this and, like any rehabilitation or physiotherapy, it can be done simply and effectively using whatever you have to hand at home or you can create your own kits
