What is Kawasaki Disease?
Kawasaki Disease (KD) is an acute auto-inflammatory syndrome sometimes referred to as vasculitis, which generally affects children of <1 to <5 years, but can also affect older children and teenagers. The trigger for KD, a syndrome identified 60 years ago, is still unknown, but viruses including corona viruses have been cited as possible triggers. Genetics have been found to play a part, with more boys than girls, and certain ethnicities disproportionately affected. Symptoms include high unrelenting fever, rash, red eyes, cracked lips, swollen lymph nodes and red and swollen hands and feet. If diagnosis and treatment is delayed, there is a greater chance of permanent damage, which usually involves the arteries and the heart, and in severe cases, can result in giant aneurysms. Kawasaki Disease is the number one cause of acquired heart disease in children.
Temper’s symptom leaflet from Societi, the UK representative body for KD Tempers-A4_endorsed-Sept-2018.pdf
Gallery of KD symptoms with thanks to Leia’s family www.bachiw.co.uk/rashes
Looks and sounds familiar, doesn’t it?
In February 2020 when we first started to be aware of Covid-19, families with children who had Kawasaki disease (KD) started to notice similarities, particularly in those who became seriously ill with a cytokine storm, causing hyper inflammation and organ damage. Then in April, PIMS-TS arrived, and jaws dropped. To all intents and purposes, KD and PIMS-TS were the same. They both affected children, and both had the same symptoms. We knew what would be next. We would go on to find that they are more common in boys than girls and show signs of ethnic predisposition, just like KD. We knew that they would need very similar treatments, which of course they eventually did. Since then, a lot of discussion and research has taken place around the question: “are PIMS-TS and Kawasaki Disease the same?”
Differences and Similarities
Other researchers such as Dr Rae Yeung are saying that even with some differences, the two conditions are on the same spectrum and that we should be looking at the bigger picture, allowing for crossovers and treating by presentation, not by name. (Source “What’s in a name” webinar)
Dr Kawasaki, who first discovered Kawasaki Disease, originally filed the condition as GOK, short for “God only knows”. Although much progress has been made in the 60 years since then, the cause or trigger is still unknown and there are still more questions than answers.
Some of the suggested triggers for KD over the years:
Adenovirus, herpesvirus, streptococci, Rickettsia species, Epstein Barr virus, retrovirus, human coronavirus- New Haven,
measles virus, house dust mite, mercury, carpet shampoo, residence near a body of water, and most recently SARS-COV-2.
Below is a synopsis of the most recent research on KD, more detail can be found on the KD Annual Symposiums.
Social and Behavioural influences
Research in the USA is showing that KD cases went down during the pandemic, particularly in lockdown. They did not disappear completely, however.
Unless one thinks that KD is PIMS-TS, with the same trigger, then we have to consider what has changed. It is unlikely that the trigger for KD has disappeared and indeed, KD cases are beginning to reappear after re reopening of society (USA research) So, is it a change of behaviour, for example, how we spent more time indoors in the lockdown, where person to person transmission (PIMS) is more likely than an environmental trigger (KD)? Did the reduction in air pollution play a part? Or is it that children were not at school and were not mixing or becoming infected by peers, in which case the KD trigger could be spread person to person?
Children of Japanese ethnicity have always had a greater predisposition to KD, wherever they live in the world. Interestingly, cases of PIMS-TS/MISC have not been seen in Japan and Korea, suggesting that they are not genetically predisposed to PIMS-TS and therefore haven’t been triggered to get ill with it? Or is it that they are so familiar with KD in Japan, that they have diagnosed PIMS-TS as KD, as to them it is not something new?
Following on from the above, other interesting observations of KD have been made during the pandemic.
*Source KD symposium 2021