Most of us know one of the main symptoms of Covid-19 is the temporary loss of the sense of taste and smell (anosmia) with two-thirds of sufferers reporting experiencing it.
But two in five report that six months after the infection they still suffer from anosmia, or reduced sense of smell (hyposmia). Worse, one in five of these long-term cases describe familiar and usually pleasant smells such as coffee or frying onions smelling like vomit or sewage (parosmia). And for some these awful smells can linger for most of the day.
‘Covid has seen a massive spike in long-term anosmia, hyposmia and, most regrettably, parosmia. At the moment there is no effective treatment or even a full understanding of the mechanisms causing these conditions. Make no mistake, these conditions are life-changing with patients unable to be intimate with their partners and repelled by their breath. The effects on daily life are profound,’ said Professor Smith.
‘Altered eating, appetite loss, weight change, loss of pleasure in food, altered intimacy in close personal relationships and an altered relationship to self and others are just some of the consequences of these conditions. There are also potential risks arising from sufferers not being able to smell food that has “gone off”, or smell gas or burning in their homes.
‘Then there is the toll on mental health and well-being. Pre-Covid research into those with olfactory disorders report high levels of depression and isolation. As one patient put it: “The world is very blank … I feel alien from myself. It’s also kind of a loneliness in the world. Like part of me is missing as I can no longer smell and experience the emotions of everyday basic living … It’s so hard to explain.”’
What matters is that researchers, clinicians and patients work together to support patients and help them manage their condition while building on their insights to guide the science.
Current thinking is that Covid-19 results in damage to the receptors that carry ‘smell signals’ to the brain and when they regenerate, receptors are missing and some are wrongly wired making, pleasant smells horrid and normally unpleasant appealing. ‘Fair is foul, and foul is fair in parosmia, it seems.’