Treating children who have lost their sense of smell

Finding children who are experiencing smell disturbances is tricky as they may be too young to share what they are experiencing, or even realise they are missing this sense. — TNS

Orange. Eucalyptus. Lavender. Peppermint.

Doctors at Children’s Hospital Colorado and Seattle Children’s Hospital in the United States will use scents like these to treat children who lost their sense of smell to Covid-19.

Parents will attend clinics and go home with a set of essential oils for their child to sniff twice a day for three months.

Clinicians will check their progress monthly.

The Smell Disturbance Clinic at Children’s Hospital Colorado was approved to open March 10 (2021).

So far, five children have been screened and one enrolled.

Seattle Children’s expects to open its programme this spring (2021).

The treatment, known as “smell training”, is clinically proven to be effective in adults.

However, clinicians say, there’s virtually no data on whether the method will work in children.

Although children are much less likely to develop Covid-19 or suffer its consequences than adults, the number of paediatric patients has steadily grown.

More cases means more kids are demonstrating lingering symptoms known as “long Covid”.

Among these complaints is loss of smell.

The link between coronavirus infections and smell disturbances in adults is well documented in both patients with short-term disease and so-called long haulers.

However, scientists are still unsure how many people develop this complication or how the virus triggers it.

Different research teams have found clues that could explain the phenomenon, including inflammation and disruptions in the structures that support the cells responsible for olfactory function.

But scant research has focused on smell disturbances in children, said Dr John McClay, a paediatric ear, nose and throat (ENT) surgeon in Frisco, Texas – let alone those caused by Covid-19.

That’s because children seldom develop these issues, he said, and the novel coronavirus has been just that – novel.

“Everything’s so new,” said the American Academy of Pediatrics education committee on otolaryngology chair.

“You can’t really hang your hat on anything.”

One intervention for adults who lose their sense of smell – whether as a result of a neurological disorder like Alzheimer’s, a tumour blocking nasal airflow, or any number of viruses, including the SARS-CoV-2 virus – has been olfactory training.

It generally works like this: Doctors test a patient’s sense of smell to establish a baseline.

Then, adults are given a set of essential oils with certain scents and instructions on how to train their nose at home.

Patients usually sniff each oil twice a day for several weeks to months.

At the end of the training, doctors retest them to gauge whether they have improved.

Dr Yolanda Holler-Managan, a paediatric neurologist and assistant professor of paediatrics at Northwestern University Feinberg School of Medicine, said she doesn’t see why this method wouldn’t work for children too.

In both age groups, the olfactory nerve can regenerate every six to eight weeks.

As the nerve heals, training can help strengthen the sense of smell.

“It’s like helping a muscle get stronger again,” she said.

Late last spring (2020), when doctors started discovering smell and taste issues in adults with Covid-19, Dr Kenny Chan, the paediatric ENT specialist overseeing the new clinic in Colorado, realised this could be an issue with kids too.

Meanwhile, Seattle Children’s Hospital Otolaryngology Head and Neck Surgery chief Dr Kathleen Sie became aware of the problem when she received an email from someone at a local urgent care centre.

After reading the message, Dr Sie called Dr Chan to talk about it.

The conversation snowballed into her spearheading a smell-training clinic at her facility.

Both clinicians must contend with the challenges “smell training” may pose to children.

For starters, some young patients may not know how to identify certain scents used in adult tests – spices such as cloves, for instance – because they’re too young to have a frame of reference, said Dr McClay.

As a workaround, Dr Chan substituted some scents for odours that might be more recognisable.

Finding children who are experiencing smell disturbances is also tricky.

Many with Covid-19 are asymptomatic (have no symptoms), and others may be too young to verbalise what they are experiencing or recognise what they are missing.

Nonetheless, Dr McClay said, the potential benefit of the simple treatment outweighs the cost and challenges of setting it up for children.

Adult smell-training kits sell for less than US$50 (RM207).

“There is zero data out there that says that this does anything,” said Dr Chan.

“But if no one cares to look at this question, then this question is not going to be solved.” – By Carmen Heredia Rodriguez/Kaiser Health News/Tribune News Service

Kaiser Health News (KHN) is a US national health policy news service. It is an editorially independent programme of the Henry J. Kaiser Family Foundation, which is not affiliated with Kaiser Permanente.