‘You almost don’t need a test’: Loss of smell and taste best COVID-19 indicator say experts

By Suzie Tombs
July 15 2020, 21.50

Thousands of people are reaching out to ENT (ear, nose and throat) experts and anosmia support groups as loss of smell and taste became the UK’s third official COVID-19 symptom, alongside a fever and a persistent cough.

UK charity AbScent is now working with the British Rhinological Society to support the increasing number of people seeking advice by providing out-of-clinic resources.

This comes after data from the Covid Symptom Study app published in May by King’s College London found that 65% of people testing positive reported smell and taste loss compared to 23% testing negative.

Only 34% of those with positive results reported a fever and 56% a persistent cough, which the research team said means anosmia is by far the best predictor of COVID-19 and will help trace almost 16% more cases.

Consultant ENT surgeon at Guy’s and St Thomas’ Hospital and president of the British Rhinological Society Professor Claire Hopkins said: “If you’ve lost your sense of smell in the last three months, it is such a good marker of COVID-19 that you almost don’t need a test as we can be 97% certain that it’s related to COVID-19.

“Postviral smell loss is relatively common, although in a typical month I would usually see only one or perhaps two patients with the condition.

“The majority of patients wouldn’t normally present to ENT for three or four months because typically loss of sense of smell from a cold involves a blocked nose and by the time it’s cleared, your sense of smell is likely recovered.

“With COVID-19 we’re seeing far greater numbers of patients much earlier at two to three weeks because it’s not associated with the obvious nasal obstruction.

“We have a really unique opportunity to be able to get data from a very large group of patients – we’re doing regular testing with about 3,000 people, so we’re learning quickly.”

The World Health Organisation, US Centre for Disease Control and Prevention, and many European countries added loss of smell and taste as an official COVID-19 symptom in March, followed by the UK on May 18.

Source: Google Trends

AbScent founder Chrissi Kelly lost her sense of smell in 2012 after having sinusitis and has supported thousands of people with smell disorders, thought to affect up to 5% of the UK population.

Loss of smell can occur from a viral infection, head injury, nasal polyps, or reduce with age, often also impacting taste as the two are closely linked.

Ms Kelly said she has seen a huge spike in the number of people reporting anosmia since COVID-19.

“I first realised that something was happening in February when I started receiving emails from people in Iran and Italy who had lost their sense of smell. Then suddenly in early March, everything started to go crazy,” she said.

“Within the first two weeks of March, I was aware that our existing Facebook group members were completely being pushed out. The conversation was relentless – it was COVID, COVID, COVID.”

To cope with demand, she set up the AbScent Covid-19 Smell and Taste Loss group, which now has 3,600 members.

She added: “We went from having 1,300 Facebook group members in early March, where I’d seen a steady growth of 1% a week since 2015, and we’re now at a combined membership of almost 7,000.

“Anosmia can cause a great loss of well-being, and leave people feeling isolated and depressed, but in my years of running the other Facebook group, the level of anxiety in the COVID-19 group seems to be of a whole different magnitude.

“In a single week in April there were an astonishing 675 posts, 1,700 comments and 5,000 to 6,000 reactions, and this continues to build.”

Ms Kelly has regained most of her sense of smell after practising smell training, likened to physiotherapy for the nose, which is now recognised as an effective treatment by the NHS.

Professor Hopkins also offered reassurance: “Pre-COVID, 30% of people recover by six months and 67% by 18 months. With COVID, we’re seeing 60-70% of people recover within the first two to three weeks.

“By eight weeks, about 5% still have anosmia and 5% reduced smell, or hyposmia, but generally we expect to see 90% fully recovered, leaving 10% with more persistent recovery.

“COVID-19 is quite an unusual virus because it is neurotropic, meaning it has the ability to invade the nerves, which sounds terrifying, but is unique compared to the common cold where only the lining inside the nose is affected.

“The olfactory nerves regenerate every 30 to 120 days, and this is what we’re seeing in the recovery data.

“We think people with early recovery have damage to the lining inside the nose – for a longer recovery time, it’s a sign that the virus is in the olfactory nerve itself and it takes time to regrow nerve endings. ”

Cross-section of olfactory nerve nerve damage from Covid-19
COVID-19 ANOSMIA: Olfactory nerve damage
Credit: medicalstocks

Anyone experiencing a sudden, unexpected loss of smell and taste should self-isolate immediately and follow NHS guidelines, even if no other symptoms are present.

WATCH: The Food Chain – Losing your taste to coronavirus

Featured image by Halfpoint

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