Losing the sense of smell or taste was one of the peculiarities of the Covid-19 infection.
For many long Covid sufferers, classed as those whose symptoms last more than three months, it has continued for years despite efforts to treat the problem. About 3 per cent to 5 per cent of sufferers develop long Covid, previous research by the University of Oxford found.
Now, experts at University College London Hospitals NHS Foundation Trust (UCLH) have successfully used a technique for correcting blocked nasal passages on patients who have suffered a profound loss of smell after a Covid infection.
One 27-year-old patient in the new UCLH study has had her sense of smell return almost to normal and is now expanding the range of foods she can eat.
All patients taking part in the research had an impaired sense of smell for longer than two years and other treatment, such as smell training or corticosteroids, had failed
The operation, known as functional septorhinoplasty (fSRP), is typically used to correct any deviation of the nasal septum, increasing the size of nasal passageways. This, in turn, increases the airflow into the roof of the nasal cavity, which controls smell.
Researchers believe increasing the delivery of odorants (chemical compounds that have a smell) to this area “kick starts” smell recovery in patients who have lost that sense due to long Covid.
Penelope Newman, 27, from south London, took part in the trial. Her results have been published in the journal Facial Plastic Surgery.
She said: “Before I had the surgery on my nose, I had begun to accept that I would probably never be able to smell or taste things the way I used to. It seemed dire, and after around two and a half years of parosmia [impaired sense of smell], I had totally changed my lifestyle.
“For those who have experienced this, they will know how isolating it can be. The food I could cook and eat was so limited, and I couldn’t go out to restaurants as I would feel unwell. Getting something as drastic as surgery was a risk I was willing to take, on the small chance it might help.
“Since the surgery, I have begun to enjoy food and smells the same way I used to. I can now cook and eat garlic and onions, and people can cook for me, too. I can go out to eat with my friends and family.
“My taste and smell have almost returned to normal," she added. "I’m not sure if it will ever fully return as I still have a small reduction in it, but I am so glad that I am no longer as isolated as I once was.”
The new research was led by Prof Peter Andrews, senior consultant surgeon in rhinology and facial plastic surgery, and Alfonso Luca Pendolino, then-senior rhinology fellow at UCLH.
It included 25 long Covid patients, with 12 of the patients undergoing fSRP, while the control group of 13 patients continued with smell training – sniffing the same scents repeatedly – for the study.
Sense of smell was measured over the duration of the study by using the Sniffin’ Sticks test, a widely used clinical test to detect smell.
All patients who had fSRP reported an improved sense of smell compared with none of the patients in the sniff test group, where 40 per cent actually reported the sense worsening.
The experts said the surgery was particularly good at increasing odour sensitivity by lowering the odour threshold – the minimal concentration of an odour a person can actually smell – which is specifically noted in long Covid patients with the impaired sense.
Prof Andrews said sense of smell “is bit like a muscle ... the more you use it, the stronger it is. Just like a muscle.”
The surgery increases the airway by about 30 per cent, so air flow also increases by about 30 per cent.
