Q&A: Kawasaki Disease and COVID-19 in children

Several paediatric cases of COVID-19 in the USA and UK have been linked to Kawasaki Disease, an inflammatory condition that affects the arteries of the body. Despite being found in people of all ages, the disease mainly affects children, and its impact can be most serious in the very young, particularly infants.

According to Kawasaki Disease Foundation Australia, the most serious complication of Kawasaki Disease is damage to the coronary arteries. When untreated, up to a quarter of children develop coronary artery damage, which can lead to acquired heart disease. The Foundation also explained that the illness is often misdiagnosed because patients present with several symptoms common to a variety of childhood diseases and infections.

As part of a combined statement from a number of organisations for Kawasaki Disease around the world, Dr David Burgner from Kawasaki Disease Foundation Australia said, “There is no current indication that overall rates of newly diagnosed Kawasaki Disease (without shock) are increasing with the pandemic, nor that children who have previously had Kawasaki Disease are at increased risk of more severe COVID-19 infection.”

In response to increasing concern surrounding a possible link between COVID-19 and Kawasaki Disease, Dr Angus Stock* from the Walter and Eliza Hall Institute of Medical Research (WEHI) in Victoria has answered some questions about the rare disease and the risk to children in Australia.

Q: What is Kawasaki Disease and what are its links to COVID-19?

“Paediatricians are noticing that a number of COVID-19-infected children are presenting to intensive care units with a range of unusual and varied symptoms. These include prolonged fever, abdominal pain, low oxygen levels (or shock), rashes and conjunctivitis. Closer clinical examination has also revealed that many of these children have developed inflammation within their hearts.

“These symptoms are reminiscent of what is observed in a rare childhood disease called Kawasaki Disease. This normally affects children between 0 and 5 years of age and the typical symptoms include prolonged fever, rash, conjunctivitis, irritability, swollen lymph nodes and changes of the oral cavity (most notably a ‘strawberry tongue’). Some children with Kawasaki Disease will also develop inflammation of the heart, characterised by inflammation of the coronary arteries.

“This overlap in many (but not all) of these symptoms has prompted many to speculate that COVID-19 may have triggered Kawasaki Disease in these children.”

Q: How rare is the disease in Australia?

“There are around 10 cases of Kawasaki Disease per 100,000 children in Australia. This translates to about 300 cases per year.”

Q: With a number of Australian states reopening schools — or looking to shortly — should there be any concerns?

“The possibility of a link between COVID-19 and Kawasaki Disease is an important consideration, particularly for the diagnosis and treatment of these children. However, even if there is a link, it is likely that only a very small fraction of children who are infected with COVID-19 will develop Kawasaki Disease-like symptoms. So, the risk is probably very small and should not impede the reopening of schools.”

Q: What is the difficulty in proving a link between Kawasaki Disease and COVID-19?

“The exact cause(s) of Kawasaki Disease have eluded researchers for over 50 years. This is in part, because it is likely that many viruses and bacteria (possibly including COVID-19) can activate this syndrome. In addition, there is an important genetic contribution, and it is likely that only a small fraction of COVID-19-infected children will ever develop this condition. However, to formalise this link it will be vital to continue to evaluate whether children who are infected with COVID-19 develop these Kawasaki Disease-like symptoms, and vice versa.”

*Dr Angus Stock from the Walter and Eliza Hall Institute has a PhD in Viral Immunology and specialises in researching immunotherapies for Kawasaki Disease.

Image credit: ©stock.adobe.com/au/galitskaya