Our sense of smell is hugely important to our day-to-day functioning and our quality of life, from appreciating food and drink, to keeping ourselves safe from hazards like spoiled food or a gas leak. Despite this, our patients with smell loss (known as anosmia) often comment that they didn't appreciate how important their sense of smell was to them until they developed a problem.
The COVID-19 pandemic has changed all of our lives. As the virus spread, the ENT community became aware of an explosion in the number of patients experiencing a sudden loss of their sense of smell. Currently, a sudden loss of your sense of smell means that you must self-isolate, even if you feel well and don't have a fever or a cough. For some patients, their sense of smell returns as they recover from the illness. But what can you do if your smell loss isn't getting better?
How does COVID-19 cause smell loss?
Sudden loss of the sense of smell has always been a relatively common reason for patients to seek help from an ENT surgeon/rhinologist. In fact, viral infections of the nose, throat and sinuses (known as upper respiratory tract infections) are among the commonest causes of sudden smell loss. Unfortunately, for a proportion of patients, recovery can be slow, and some can be left with a permanent reduction or alteration in their sense of smell.
COVID-19 is a new disease, and as a result our knowledge about how it causes symptoms is limited. Anosmia can be caused by inflammation of the lining of the nose, or by direct damage to the sensitive nerve endings (olfactory fibres) in the roof of the nasal cavity. We know that a substantial number of patients with COVID-19 related smell loss will recover fully or partially within a few weeks; however a growing group of patients are experiencing smell loss that lasts longer than this.
What if my sense of smell isn't recovering?
As with all new symptoms, it is a good idea to see your GP for their opinion, and recommendation about the need for specialist referrals. You may choose to see a specialist directly. It is important to see a specialist for longer-lasting smell loss, as there is a wide range of possible causes.
An ENT surgeon or rhinologist is able to examine the nasal cavity and olfactory region in great detail using a fine fibreoptic camera (endoscope). This helps to determine whether there is any inflammation in the region, and whether there is any other potential cause for your smell loss. If the cause is not clear, it can be necessary to have a scan (often an MRI) to look more closely at the olfactory (smell-sensing) apparatus.
Can COVID-19 related smell loss be treated?
Because COVID-19 is a new disease, most of our treatments for COVID-19 related anosmia are guided by what we already know about smell loss caused by other viruses. The best treatment for you depends on a number of factors, including the severity of your smell loss, how long it has been going on, whether you have any other nasal symptoms, and the findings on examination of your nasal cavity.
Some patients benefit from anti-inflammatory (steroid) medication, given as a longer course of nasal drops, and/or a shorter course of oral steroid pills. Other medical treatments, such as Vitamin A nasal drops and Omega-3 supplements may have some effect in some patients – the evidence for this is still at an early stage.
Most patients with smell loss benefit from smell training. This is particularly true if they have incomplete loss of smell (known as hyposmia). Smell training is a regular programme of "exercise" and rehabilitation for your sense of smell. It involves "mindfully" smelling known substances again and again, gradually strengthening the connections between smell receptors and the brain.
Where can I find support?
AbScent is an excellent UK-based charity that provides information and support to people who have anosmia or other smell disorders. The website contains further information on COVID-19 related smell loss, as well as information about smell training.