Answering Your Questions – 24 May 2020 (Reviewed and Updated – 27 February 2023 )

Introduction from Societi Foundation’s Founder….

It’s really easy to frighten people. It’s less easy to find out the facts. And because parents like me want FACTS, so they can make up their own minds about what is going on, we have done some work with experts to answer the questions you’ve raised.

 As Founder of the UK Foundation for Kawasaki Disease, it’s been really worrying for me to see the mishandling of information about the paediatric inflammatory multisystem syndrome – or “PIMS” which you will have heard of. In different parts of the world, this syndrome has been given different names.  I’m frustrated, like many in our community, that it has been casually described as ‘Kawasaki-like’ – which has done nothing but create more confusion. Kawasaki Disease is often misdiagnosed at first because it has symptoms common with MANY illnesses – so the phrase ‘Kawasaki-like’ is just not helpful. It might as well have been ‘measles-like’ or ‘sepsis-like’.  These are equally uninformative phrases.

 Choosing the correct language at times like these is actually really important.  The terms used, and headlines that have resulted, have caused alarm, panic and fear for parents and patients; what’s really worrying is that these headlines have also confused doctors. Children ACTUALLY affected by Kawasaki Disease are potentially AT MORE RISK because of the confusion caused, since they may not receive treatment for Kawasaki Disease due to concerns it might be Covid-19; or from delayed presentation to hospital. As a result, children with Kawasaki Disease may not get the early diagnosis they urgently need, delaying treatment and incurring life-long cardiac damage. 

 It is very important that doctors quickly learn more about PIMS-TS and already, many research studies are underway to gather evidence, build up and share knowledge. It’s so important to me as a parent that they do. As parents we share the same goals as doctors here – to provide the very best possible care for our children. Perhaps in learning more about PIMS-TS we will learn more about Kawasaki Disease too.

 Providing clear facts has been my focus, right from starting our charity in 2015. Here are our clear, evidenced facts – written with expert doctors, to provide the answers to questions you have asked.

 Finally, as ever – if you are worried about your child for whatever reason, contact NHS 111 or your family doctor for urgent advice, or 999 in an emergency, and if a professional tells you to go to hospital, please go to hospital. NHS staff have worked hard over the last few months to change hospitals to make sure that everyone who needs it can get the urgent care they need in as safe a way as possible, so don’t be worried about coronavirus, or about being a burden on staff – our NHS is there for you.

 Rachael, Societi Founder.

Statement by our Scientific Advisory Board – 24 May 2020

(Reviewed and updated – 27 February 2023 )

Answering your questions on Kawasaki Disease, PIMS-TS, Covid-19 and Children

What is PIMS-TS?

PIMS-TS stands for paediatric inflammatory multisystem syndrome temporally related to Sars-CoV-2. There have been reports of cases of children severely ill in hospital due this  inflammatory illness in the UK, Europe and the USA. Doctors think this may be a delayed immune reaction to Covid-19 occurring after the acute (initial) infection. The presenting signs and symptoms are sometimes like those of bad cases of Kawasaki Disease, and sometimes like other severe diseases (e.g. Toxic Shock Syndrome). In fact, PIMS-TS is distinct from Kawasaki Disease, particularly in relation to treatment and frequency and nature of effects on the heart. Since it is occurring at a time when Covid-19 is around, doctors are investigating all cases in the UK to understand more about why this might be. (1)

Of course, this means that some children with Kawasaki Disease will be included in this Covid-19 research work, due to initial uncertainty about what is making them unwell.

Does this type of illness just affect children?

No, adults are affected by inflammatory illness thought to be caused by Covid-19 as well, sometimes referred to as “cytokine storm”. The press spotlight is on children but the type of symptoms being seen in children with PIMS-TS are also seen in adults. In particular, this severe systemic inflammation has resulted in clinical trials exploring treatments to switch this off using immune suppressing drugs in adults, with children being very recently included as well. (2)

How is PIMS-TS different from Kawasaki Disease?

In short: children with PIMS-TS tend to be older, have more tummy pain, and shock. Coronary artery changes don’t happen usually in PIMS-TS. If treated promptly, the outlook is good for PIMS-TS.

We know Kawasaki Disease is similar to LOTS of other illnesses. Doctors fail to spot it often because they see just a few symptoms and make a diagnosis of something that’s much more common – or something they are more familiar with. So – children often get diagnosed with ‘just a virus’, scarlet fever or meningitis.  Societi research showed parents on average have to battle through 2 or 3 wrong diagnosis before their child is correctly diagnosed with Kawasaki Disease.  That’s how little this disease is understood by the medical profession. (3)

There are several points to note:

Firstly, and this might surprise you, Kawasaki Disease is very serious – it can result in death, or permanent heart damage and it is increasingly common. We know that PIMS-TS has been devastating for a small number of families whose children have been very gravely affected, however – almost all children affected by PIMS-TS reported so far have been shown to have made a full recovery.  This is according to the European Centre for Disease Prevention and Control rapid risk assessment (4). Research will continue so we can learn more about this, as more cases are seen. We also know that the number of PIMS-TS cases appears to be sharply falling now, with very few cases reported in 2022 and doctors suggest this trend will continue.

We know much more of course about Kawasaki Disease – where, despite treatment, about a quarter (28%) of children affected have heart damage and 19% have serious heart damage for life. A shocking 39% of infants affected (babies under 1) have severe lifelong heart damage – meaning they need specialist care for life. Untreated, 2-3% of children with Kawasaki Disease will die. (5) Kawasaki Disease cases are also on the rise with the number of cases doubling at least every 10 years.

It seems to be that most children who have Covid-19 show very few symptoms. A very small proportion go on to develop PIMS-TS about 10 days to 3 weeks later. This can be serious – and is different from Kawasaki Disease in its presentation, and although can be associated with heart inflammation, does not appear to target the heart the way Kawasaki Disease does.

We also know that, for some children who get Kawasaki Disease, their reaction is very severe and right now, some have evidence of an earlier Sars-CoV-2 (Covid-19) infection. Such children should be treated for severe Kawasaki Disease as normal, using tried and tested clinical guidelines agreed internationally. (6)  Because we do not know what causes Kawasaki Disease, it’s difficult to know why this severe illness happens in some children.

Features of PIMS-TS:  Many features of PIMS-TS are non-specific, and can be seen in several disorders associated with severe inflammation: for example some children with severe arthritis, other infections, inflammatory bowel disease, or even children who present with abdominal pain resembling appendicitis. We’ve said above that Kawasaki Disease also shares some symptoms with PIMS-TS, but there are many other inflammatory disorders of children that do so. Features of PIMS-TS that are NOT usually signs or symptoms of Kawasaki Disease include: (7)

  • Respiratory symptoms / cough – not usually a symptom of Kawasaki Disease
  • Gastrointestinal symptoms and abdominal pain – predominant early symptoms in PIMS-TS but uncommonly seen in Kawasaki Disease
  • Abnormal fibrinogen and clotting disorders. PIMS-TS can present with clots in the lung arteries and this is not usually seen in Kawasaki Disease
  • Single or Multi-organ failure – not usually seen typically in Kawasaki Disease but characteristic of PIMS-TS
  • Shock and heart failure are much more frequent in PIMS-TS than in Kawasaki Disease
  • Children are generally older with PIMS-TS (10 – 12 usually) than with Kawasaki Disease (about 75% are under 5)

Conversely, serious heart complications (aneurysms) seen in Kawasaki Disease are not being seen as commonly in children with PIMS-TS. Whereas 19%, of all children affected by Kawasaki Disease, despite treatment, develop serious heart problems and 39% of infants under one year have coronary artery aneurysms. (8)  Whilst occasionally these have been seen in children who have been diagnosed with PIMS-TS, these might just turn out to have had Kawasaki Disease, irrespective of their Covid-19 status. One hypothesis (idea) is that Covid-19 infection may have triggered Kawasaki Disease in some children, but there is no actual evidence to support this currently. Ongoing research will help us understand more.

How did all this worrying reporting start?

An uncontrolled internal note from one NHS Trust was circulated widely. It was unfortunately posted on social media by a usually trusted source. That source has since deleted the post. The idea that there might be a new issue or complication of Covid-19 affecting children got shared quickly, as this is a disease which all the evidence available shows doesn’t usually affect children seriously. So the idea that this might be different got lots (and lots) of people interested (and even more parents and families worried).

So why has Kawasaki Disease got ‘mixed up’ in this?

Because of imprecise use of made-up terms – like “Kawasaki-like” – to describe illness affecting children. During the last SARS outbreak 18 years ago, there were isolated case reports of coronavirus and Kawasaki Disease; more in depth research studies failed to confirm a definite link.   But there WILL be children affected by Kawasaki Disease RIGHT NOW – because every year in winter and spring we normally see a surge of cases. We happen to be in a pandemic so everyone is focusing on Covid-19. But last year, and the year before (and the years before that!) we’ve seen an increase in the number of cases of Kawasaki Disease during winter and spring. (9)

What causes Kawasaki Disease?

In fact, there are lots of theories but no one knows despite worldwide research for decades. There is some evidence to suggest that some children have a genetic predisposition to being affected by Kawasaki Disease.  Some researchers believe it could be a child’s response to an infection (or a number of infections), though no infectious cause has been found.   There are theories too that suggest an environmental agent – perhaps something which is airborne, or related to bodies of water.  Whilst there is much research ongoing, some of it appears contradictory, or inconclusive.  The patterns of incidence of Kawasaki Disease (who gets it and where) are different in different places, and in the past there have been well-documented clusters of cases suggesting that infection may have a role, but this has never been proven.

What are the symptoms of Kawasaki Disease?

Kawasaki Disease is increasingly common with c. 1,000 hospital admissions each year in the UK (9). It has a range of symptoms including a characteristic and distinctively persistent high fever for five days or more, plus any two or more of the following symptoms:

  • Rash
  • bloodshot eyes
  • “strawberry” tongue, cracked, dry lips
  • redness of the fingers and toes.
  • Swollen glands – often just on one side

If a child has a persistent fever of unexplained cause, we urge everyone to THINK Kawasaki Disease. Early treatment is critical to reduce the risk of lifelong heart disease.

Is Kawasaki Disease contagious?

No. Kawasaki Disease isn’t contagious.

How many children get Kawasaki Disease in the UK?

Kawasaki Disease is increasingly common and cases are on the rise, with c. 1,000 hospital admissions each year in the UK. (10)

How does this compare with the number of children who have been reported as having PIMS-TS?

There are now very few cases of PIMS-TS occurring. Doctors suggest this is partly because of the high level of immunity (to Covid-19) now present in the general population. Having seen a peak in cases during the pandemic, case numbers fell dramatically since then and just a handful of PIMS-TS cases now occurring. Early scrutiny of some of the early reports of PIMS-TS suggests that some of these children might actually have had Kawasaki Disease, but future research will help answer that question.

Do children get seriously unwell because of Covid-19? (11)

Following initial in China, it appeared children were significantly less affected by infection with Covid-19 than adults. This was reflected both in total case numbers, but also severity, with very few cases in young children and no deaths in children under 10 years in the initial report. Studies from other countries have also shown this.  Low numbers of childhood cases have been seen in the rest of Europe, as well as the USA, where 1/3 of childhood cases are in late adolescence [older teens]. Some concerns exist that low case rates reflect selective testing of only the most unwell, however data from South Korea and subsequently Iceland which have undertaken widespread community testing, have also demonstrated significantly lower case numbers in children. This has also been seen in the Italian town of Vo, which screened 70% of its population and found 0 children less than 10 years of age who were positive, despite a 2.6% positive rate in the general population.

More detailed information is becoming available on childhood severity of Covid-19. From studies it’s been shown that a large number of children appear asymptomatic (do not show symptoms even if infected). Critical illness appears very rare (only about 1%).  In Chinese and USA (Centre for Disease Control) data, infants [very young babies] appear most likely to be hospitalised, although rates of paediatric intensive care unit admission do not appear to be significantly different as yet.

To date, deaths remain extremely rare in children from COVID-19, with only a very small number of reported cases.

A research project across the whole of the UK has just been published in the last few weeks to report more about where this disease is occurring, how many cases there are, which children are being affected – and perhaps help doctors understand more about why. Many more similar research programmes are underway across Europe.

Does Covid-19 cause PIMS-TS?

Yes – it is thought that the virus causing Covid (SARS-CoV-2) triggers the inflammatory immune response causing PIMS-TS.

Studies so far suggest that some children affected by PIMS-TS have (or have had) Covid-19 – whilst some children have PIMS-TS with no evidence Covid-19 infection. One problem is that tests to detect infection with Covid-19 are currently not 100% accurate – so some children with PIMS-TS may truly have had infection with Covid-19, but this was not detected by nose swab (RT-PCR) or antibody test.

Research is underway across Europe and elsewhere to understand why some people develop PIMS-TS, and most others don’t.

How serious is Covid-19 for children compared to other risks?

In response to an article published on 28 April 2020 in the British Medical Journal (12), which reviewed evidence from around the world to answer this question, public health expert Dr Sunil Bhopal wrote “Across the USA, England, Italy, Germany, Spain, France and Korea there were 43 deaths from COVID-19 in 0-19 year olds (total population 135,691,226) in the three months to 12 May 2020. In this period, in these countries, we estimated… [from] data that we would expect more than 36,000 deaths from all causes in this age group, including over 3,000 from unintentional injury and 891 from lower respiratory tract infection including influenza.

Covid-19, by this measure, was responsible for an estimated 0.117% of deaths of 0-19 year old in these three months.” (13)

In other words, children in these countries, including England, are 20 times more likely to die from flu and respiratory illness than Covid-19. They are also about 70 times more likely to die from unintentional injury than from Covid-19.

What can history tell us?

You might remember the SARS epidemic in 2005. This disease is also caused by a type of coronavirus. Lots (and lots!) of rumours also circulated during this epidemic about a link between that disease (which little was known about) and Kawasaki Disease.  Some people said SARS caused Kawasaki Disease. Similar panic and alarm was caused then, as now.

Research in the calmer period after the SARS epidemic showed there was no definite link between SARS and Kawasaki Disease (14). By this time though, the media interest had gone so these facts were not well reported.

Acknowledging a phenomenal clinical team

Huge thanks to Societi Foundations Scientific Advisory Board, including Professor Paul Brogan, Dr Owen Miller, Prof Despina Eleftheriou, Prof Damian Roland and Dr Tom Johnson. Thanks too to the many other contributors to this work – without whose rapid input, review and feedback, this statement would not have been possible. These include Prof Simon Kenny for support and signposting, Dr Alistair Munro for contemporary data synopses and Dr Sunil Bhopal, public health expert. We are also deeply grateful to colleagues from NHS England / NHS Improvement with whom we have worked in the production of this statement.


ABOUT THIS STATEMENT: This is a statement issued by Societi Foundation, prepared by our Scientific Advisory Board on 24 May 2020. This statement was reviewed and updated on 27 February 2023.

IMPORTANT NOTE: The information contained in this statement is true and accurate to the best of Societi Foundation’s knowledge and belief, and is based on the information currently available to it. This statement does not give, and should not be construed as, medical advice.


(1) Prof Robert Tulloh, 15 May 2020

(2) Mehta P et al; Covid-19: consider cytokine storm syndromes and immunosuppression. The Lancet.

(3) Societi Foundation Diagnosis Day study July 2018

(4) Harwood R, Allin B, Jones CE, Whittaker E, Ramnarayan P, Ramanan AV, Kaleem M, Tulloh R, Peters MJ, Almond S, Davis PJ, Levin M, Tometzki A, Faust SN, Knight M, Kenny S; PIMS-TS National Consensus Management Study Group. A national consensus management pathway for paediatric inflammatory multisystem syndrome temporally associated with COVID-19 (PIMS-TS): results of a national Delphi process. Lancet Child Adolesc Health. 2021 Feb;5(2):133-141. doi: 10.1016/S2352-4642(20)30304-7. Epub 2020 Sep 18. Erratum in: Lancet Child Adolesc Health. 2021 Feb;5(2):e5. PMID: 32956615; PMCID: PMC7500943.

(5) Eleftheriou D, Levin M, Shingadia D, et al Management of Kawasaki disease Archives of Disease in Childhood 2014;99:74-83

(6) European consensus-based recommendations for the diagnosis and treatment of Kawasaki disease – the SHARE initiative. de Graeff N, Groot N, Ozen S, Eleftheriou D, Avcin T, Bader-Meunier B, Dolezalova P, Feldman BM, Kone-Paut I, Lahdenne P, McCann L, Pilkington C, Ravelli A, van Royen-Kerkhof A, Uziel Y, Vastert B, Wulffraat N, Kamphuis S, Brogan P, Beresford MW.Rheumatology (Oxford). 2019 Apr 1;58(4):672-682. doi: 10.1093/rheumatology/key344.PMID: 30535127


(8) Kawasaki disease: a prospective population survey in the UK and Ireland from 2013 to 2015. Tulloh RMR, Mayon-White R, Harnden A, et al Arch Dis Child. 2019 Jul;104(7):640-646. 30104394

(9) Societi Foundation FOI request data appraisal 2019 NHS Trusts / Health Boards – England, Wales, Scotland, Northern Ireland (pre-publication)

(10) Societi Foundation FOI request data appraisal 2019 – average of 3 year admissions 2016-2018 by month, February – April inclusive

(11) Boast A, Munro A, Goldstein H. An evidence summary of Paediatric COVID-19 literature, Don’t Forget the Bubbles, 2020

(12) Peter Green, BMJ 2020;369:m1669

(13) Sunil S Bhopal NIHR Academic Clinical Lecturer in Population Health Paediatrics response to BMJ 2020;369:m1669

(14) Novel human coronavirus and Kawasaki disease. J Infect Dis 2005; 191:499–502. Ermias D. Belay,1 Dean D. Erdman,1 Larry J. Anderson,1 Teresa C. T. Peret,1 Stephanie J. Schrag,1 Barry S. Fields,1 Jane C. Burns,2 and Lawrence B. Schonberger1

(15) Brogan P, Burns JC, Cornish J, Diwakar V, Eleftheriou D, Gordon JB, Gray HH, Johnson TW, Levin M, Malik I, MacCarthy P, McCormack R, Miller O, Tulloh RMR; Kawasaki Disease Writing Group, on behalf of the Royal College of Paediatrics and Child Health, and the British Cardiovascular Society. Lifetime cardiovascular management of patients with previous Kawasaki disease. Heart. 2020 Mar;106(6):411-420. doi: 10.1136/heartjnl-2019-315925. Epub 2019 Dec 16. PMID: 31843876; PMCID: PMC7057818.