‘Smell training’ recommended to fight scent loss caused by Covid-19

Scientists are recommending “smell training” for patients who have lost their ability to detect scent because of Covid-19.

Anosmia – loss or changed sense of smell – was added to the NHS’s list of coronavirus symptoms in May last year, after a wave of patients came forward reporting not being able to detect familiar odours or taste certain foods.

The NHS says most people who get anosmia because of Covid-19 recover from the condition within a few weeks or months, although it persists for some.

Researchers at the University of East Anglia's Norwich Medical School say smell training could help such patients.

The practice involves sniffing at least four different odours, twice daily for several months.

Professor Carl Philpott, a smell expert at East Anglia's medical school, said that the method “aims to help recovery based on neuroplasticity – the brain’s ability to reorganise itself to compensate for a change or injury”.

Research by an international group of smell experts, published in the journal International Forum of Allergy & Rhinology, advised against using steroids to treat smell loss.

And Prof Philpott says there is “very little evidence” steroids will help with smell loss and they have “potential side effects including fluid retention, high blood pressure, and problems with mood swings and behaviour”.

He said Covid-19 has led to a “huge rise” in smell loss globally.

Around one in five people who experience smell loss report it has not returned to normal eight weeks after falling ill, he said.

“Luckily most people who experience smell loss as a result of Covid-19 will regain their sense of smell spontaneously,” Professor Philpott said.

“Research shows that 90 per cent of people will have fully recovered their sense of smell after six months. But we do know that smell training could be helpful,” he added.

In July last year, a month after anosmia was added to the coronavirus symptoms lists, a charity reported increasing demand for smell therapy.

AbScent founder Chrissi Kelly told Business Insider at the time that membership at her company had swollen to three times pre-Covid levels.

While not a cure, smell therapy has been described as a type of physiotherapy for the nose. Recovering patients are required to sniff odours to stimulate the nerves in the nose.

The treatment can include essential oils such as rose, lemon, clove and eucalyptus.

The NHS recommends smells training as a form of treatment that might be able to help people regain their sense of smell.

Steroid nasal sprays or drops might also help. Rinsing the inside of your nose with a saltwater solution may help if your sense of smell is affected by an infection or allergy, according to the NHS.

Additional reporting by Press Association