Mysterious illness trails COVID-19
Canadian doctors warned to watch for symptoms of Kawasaki in children
Canadian pediatricians have been issued a “Be On the Lookout” advisory for an acute inflammatory disease similar to Kawasaki disease that has been observed affecting children during the coronavirus pandemic.
When police issue a BOLO, it means they’re looking for information on a suspect, but it usually also means that caution is indicated.
The Public Health Alert issued Tuesday by the Canadian Paediatric Surveillance Program is asking Canadian pediatricians to report any cases they come across of children whose symptoms suggest Kawasaki disease, whether or not they have tested positive for COVID-19.
But the alert also warns doctors that children with those symptoms during the current pandemic may deteriorate quickly and that fast treatment may be necessary. That alert comes on the heels of a similar alert released by the New York City health department last week, and similar observations in the U.K. two weeks ago. Three children have died in New York state.
Researchers have not identified a conclusive link between COVID-19 and this inflammatory disease. But they do know that, pre-COVID-19, viral infections, and even coronavirus infections, have been known to trigger symptoms of Kawasaki disease.
Kawasaki is an acute inflammatory illness that affects small children. Although doctors still aren’t sure exactly what causes it, they do know that, in some patients, a viral infection will trigger an overreaction by the immune system. That causes an inflammation of mediumsized blood vessels in the body. That inflammation is primarily responsible for Kawasaki symptoms: a prolonged, high fever that resists treatment; red, cracked lips; red tongue and eyes; a pink rash and swollen lymph glands. Some or all of these may present themselves.
Of particular concern is if the inflammation makes its way to the arteries around the heart. There, it might cause aneurysms — enlargements of the artery caused by weakness in the arterial wall — that could prove fatal.
The newer inflammatory disease presents similarly to Kawasaki, with the added danger of shocklike symptoms, where blood pressure can tumble to dangerously low levels.
“Inflammation, in general, is something that occurs on a spectrum. And there’s a lot of person-to-person variability,” said Dr. Charlotte Moore Hepburn, the director of medical affairs for the Canadian Paediatric Society. “Kawasaki disease, even though it’s well understood, is a clinical diagnosis that presents as a constellation of signs and symptoms. It’s not like a single lab test: ‘You’re positive Kawasaki, negative Kawasaki.’
“I think people would feel comfortable … drawing that line from viral illness triggering inflammatory state, (to) triggering this hyper-inflammatory state which is Kawasaki/toxic shock-like … But right now, there’s still a lot left to learn in terms of teasing out just exactly how this COVID-19-triggered state may be different from what we would consider runof-the-mill” Kawasaki disease.
Moore Hepburn emphasized that the cases of the newer inflammatory disease are still very rare. One of the functions of the public health alert is to gather more cases to study — nationwide and, eventually, globally.
Aside from establishing a causal link between COVID-19 and this acute inflammatory disease, doctors would like to know why some children are affected differently than others.
Although some patients might present with all the classic symptoms of Kawasaki disease, others may only be showing a subset of those symptoms. Still others might show next to none, but still be at risk for sudden shock syndrome.
“I think what we need to figure out is, is COVID-19, in healthy children, triggering a severe hyper-inflammatory state, meaning an activation of the immune system that becomes harmful to the blood vessels and the heart of the child,” said Dr. Susa Benseler, a pediatric rheumatologist at Alberta Children’s Hospital in Calgary.
The other pertinent question, she added, is if there are certain characteristics to children who are more affected.
“Because if that’s the case, then we … need to be able to recognize this super early, because we have ways of treating this that are very effective.
“We know this from classical Kawasaki: The earlier you treat, the better the child’s outcome. And that’s the key thing, why this awareness and all of the surveillance is of such critical importance.”
Doctors would also like to know why the onset of this inflammatory disease seems to trail the course of a coronavirus infection by a few weeks.
“It seems like the peak of these children presenting is usually around two to four weeks after the peak of the actual COVID-19 surge of cases in general,” said Dr. Jeremy Friedman, the associate pediatrician-inchief at Toronto’s Hospital for Sick Children.
He saw about 100 to 150 cases of Kawasaki disease a year, precoronavirus, mostly in children six or younger.
Researchers in New York and the U.K. have also discovered that while these patients usually test negative for the coronavirus on the swab test, in cases where doctors have been able to test for antibodies, most of the patients do test positive.
The implication is that the patients who were being treated for this disease often had coronavirus infections, but the infection had run its course.
The fact that Canada is still in earlier stages of its coronavirus epidemic suggests there may be an uptick in cases of Kawasaki disease in the near future.
That worries Friedman. He’s concerned that in the midst of the pandemic, people are more reluctant to go to hospitals, and parents may delay bringing in children who are beginning to show signs of the disease.
“The important point with this particular illness is that it is absolutely treatable, but it does need to be recognized and the children can get extremely sick,” he said. “So we’re hoping that parents, if they do see their child with five days of high fevers … they really should seek medical attention.” On Wednesday, Ontario Health Minister Christine Elliott issued a statement expanding the case definition of COVID-19 to include the Kawasaki-like illness as an “atypical presentation in children.”
“Some of the symptoms associated with this illness include persistent fever, abdominal pain, gastrointestinal symptoms, including nausea, vomiting and diarrhea, as well as rash,” she said. “Parents should contact their health-care providers immediately if their children are having these symptoms.”
“We know this from classical Kawasaki: the earlier you treat, the better the child’s outcome.”
DR. SUSA BENSELER PEDIATRIC RHEUMATOLOGIST