Though the Omicron coronavirus variant may have a reputation for causing a much milder form of Covid-19, in January, Dr. Ashley Keilman and other doctors started noticing something that seemed unique to this variant.
“We were seeing more patients with croup, and more patients were testing positive for Covid, which was something that we had not observed during earlier phases of previous surges with Covid,” said Keilman, a specialist in pediatric emergency medicine at Seattle Children’s Hospital.
It’s not just in Seattle. Pediatricians across the country say they are seeing a spike in croup cases.
Croup is often brought on by parainfluenza respiratory viruses. It happens when the upper airways become inflamed, making it difficult to breathe. Because kids have smaller airways than adults, it’s more common among little ones.
This inflammation in the voicebox, the windpipe and the bronchial tubes causes the child to have a loud distinctive cough that some say sounds like a barking seal. When the child tries to breathe, it can also produce a high-pitched whistle known as stridor.
In some cases, the symptoms can clear up after about five days. But for other kids, the symptoms don’t go away with just home treatments.
Keilman is the author of a preprint study – meaning it has not been peer-reviewed or published in a journal – that found a total of 401 children seen in the ER were diagnosed with croup during the Delta surge and 107 during the Omicron surge. Patients during the Omicron surge were much more likely to test positive for Covid-19: 2.8% of croup cases tested positive during Delta, versus 48.2% during Omicron.
“Omicron has proven itself to be an upper respiratory illness and an illness in the upper airway rather than the lower airways in the lungs and so therefore, people are sort of blowing it off as a just a cold virus and no big deal. But I think what we’re seeing is that of the upper respiratory sort of infections, viral infections, croup is among the most severe and puts children in the ICU regularly,” said study co-author Dr. Indi Trehan, attending physician in infectious disease and virology and emergency medicine at Seattle Children’s.
“You know, as any parent will tell you, it’s one of the scariest things to see your child not be able to breathe from it,” Trehan added. “So this early signal of high rates of croup with Omicron is pretty concerning. We’re trying to get this word out to our colleagues.”
Other doctors from across the country have told him they’ve seen similar trends.
Another preliminary study found that 2.4% of kids 13 and younger who were hospitalized in one area of South Africa for Covid-19 caused by Omicron also had a croup diagnosis.
There have also been more opportunities for croup to develop with this surge because so many kids have had Covid-19. Nearly 4.2 million Covid-19 cases have been reported in US children since the beginning of January, according to the American Academy of Pediatrics.
Dr. Claudia Hoyen, a pediatric infectious disease specialist at UH Rainbow Babies and Children’s Hospital in Cleveland, who did not work on these studies, said croup season in her area typically hits in the fall. So when more kids starting showing up with croup in December, during the Omicron wave, she suspected that something was different with this variant.
“We know that your nasal tissues are much more receptive to Omicron, and the lung is not,” Hoyen said. “We’ve not seen croup with other surges. This one has been different,”
Hoyen and the doctors at Seattle Children’s said that fortunately, most kids with croup haven’t needed to be admitted to the hospital. If they come in for treatment, doctors typically give them a corticosteroid that can reduce the inflammation in the respiratory tract.
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Even better than a corticosteroid, doctors say, is if the kids don’t get Covid-19 in the first place.
Because the littlest ones who more often get croup still can’t get vaccinated, Hoyen said, it would be best to make sure everyone around them is fully vaccinated, if possible.
“Do what you can to save the little ones from being a barky seal. It’s really distressing to hear them, trust me, and it can be quite serious,” Hoyen said. “So do what you can to help them. Getting yourself vaccinated is easy and important.”