Nosing in on kids who had Covid and lost their sense of smell

Orange. Eucalyptus. Lavender. Peppermint.

Doctors at Children's Hospital Colorado and Seattle Children's Hospital 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. So far, five children have been screened and one enrolled. Seattle Children's expects to open its program this spring.

The treatment, known as "smell training," is clinically proven to be effective in adults. However, clinicians said, there's virtually no data on whether the method will work in children.

Although children are much less likely to develop Covid or suffer its consequences than adults, the number of pediatric 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 pediatric ear, nose and throat surgeon in Frisco, Texas — let alone those caused by Covid. That's because children seldom develop these issues, he said, and the novel coronavirus has been just that — novel.

“Everything’s so new," said McClay, who is also the chair of the American Academy of Pediatrics education committee on otolaryngology. "You can’t really hang your hat on anything.”

It works for adults. Will it work for kids?

One intervention for adults who lose their sense of smell — whether as a result of a neurological disorder like Alzheimer's, a tumor blocking nasal airflow or any number of viruses, including Covid — 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 improved.

Dr. Yolanda Holler-Managan, a pediatric neurologist and assistant professor of pediatrics 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, when doctors started discovering smell and taste issues in adults with Covid, Dr. Kenny Chan, the pediatric ear, nose and throat specialist overseeing the new clinic in Colorado, realized this could be an issue with kids, too.

Dr. Kathleen Sie, chief of Otolaryngology Head and Neck Surgery at Seattle Children's Hospital, became aware of the problem when she received an email from someone at a local urgent care center. After reading the message, Sie called 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 McClay.

As a workaround, Chan substituted some scents for odors that might be more recognizable.

Finding children who are experiencing smell disturbances is also tricky. Many with Covid are asymptomatic, and others may be too young to verbalize what they are experiencing or recognize what they are missing.

Nonetheless, 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 $50.

“There is zero data out there that says that this does anything," said Chan. "But if no one cares to look at this question, then this question is not going to be solved.”

This article was reprinted from khn.org with permission from the Henry J. Kaiser Family Foundation. Kaiser Health News, an editorially independent news service, is a program of the Kaiser Family Foundation, a nonpartisan health care policy research organization unaffiliated with Kaiser Permanente.