Kawasaki Disease is a type of vasculitis. Ah! We know!! We said no jargon! So we’ll explain…. “Vasculitis” means inflammation or swelling of the blood vessels, which are the tubes that carry blood around your body.
Kawasaki Disease is getting more common in the UK with about 1,000 children going in to hospital with Kawasaki Disease each year. When first ill with Kawasaki Disease, most children affected are quite young, about three quarters are under five years old. It can be really serious in very young children – babies under one year old.
The cause of Kawasaki Disease is still unknown. Kawasaki Disease has a range of symptoms which are the same as lots of other children’s infections and bugs…. This makes it tricky to spot unless you know Kawasaki Disease and you’re looking out for it. Kawasaki Disease is serious – because if it’s treated late or if it isn’t treated at all, it can cause lifelong heart disease. Ouch!
And even more serious – it’s really sad because a few children every year die because of Kawasaki Disease. It’s the TOP cause of acquired heart disease in children in the UK – that’s heart disease that you’re not born with. Really serious stuff.
There are lots of theories around the cause of Kawasaki Disease and even more research going on across the world to try and find the cause. But at the moment, no-one is certain what causes Kawasaki Disease – or even whether it’s one thing, or a number of things.
Some of the research doctors have done suggests some children might have a certain genetic makeup which makes them more likely to be affected by Kawasaki Disease. Everyone’s genetic makeup depends on their own unique mix of genes. Genes are a bit like the computer programmes for the cells in our bodies and shape what we look like, how tall we will be, our hair and eye colour – but also what diseases we might be more likely to get. That might include Kawasaki Disease. Doctors aren’t quite sure.
Some researchers believe it could be a child’s immune response to an infection or a number of infections – but no infectious cause has been found. Your immune system works to fight infections in your body, but some illnesses are caused when the immune system fires up when there isn’t actually an infection. Doctors aren’t sure whether this is part of what happens with Kawasaki Disease.
There are other ideas too, like one about something in the environment – perhaps something which is in the air or linked to water bodies like lakes. Whilst there is a lot research going on to try and find a cause (or causes!) because there are so many ideas about the cause, doctors disagree about all these theories. Not helpful – we know! The patterns of Kawasaki Disease – when you look at who gets it: when they get it and where – guess what, this is different in different places too….Oh!!!
So it’s a real puzzle!
What we do know is that the number of children getting Kawasaki Disease is rapidly on the rise and that identifying the cause will be a huge turning point in the fight against Kawasaki Disease. Let’s hope a few of those researchers team up and find the answer soon!
There’s two parts to this one.
The first bit of the answer is about when children first get Kawasaki Disease. Children are treated in hospital by specialist doctors. The treatment given is called “intravenous immunoglobulin”. That’s a bit of a mouthful – we’ll call it IVIG instead! It’s a very precious treatment made from blood donations. It’s an amazing treatment in fact, which quickly stops the inflammation (or swelling up of of tiny cells) happening in a child’s body when they get Kawasaki Disease.
The other medicine given at the same time as IVIG, is aspirin. You’ve probably heard of that medicine! It has the same sort of effect as IVIG, helping to reduce the inflammation. Sometimes children are also given corticosteroids (steroids). You’ll probably guess – and you’d be right – these also work to reduce inflammation. All these treatments “switch off” the high temperature and inflammation (which is the thing causing all the other symptoms like red eyes and a rash) and help to cut down the chance of heart damage. Sometimes other drugs are used as well, but – yes – you guessed it, these also work to stop inflammation!
Today, doctors understand that early treatment is key to reduce the risk of heart damage in children with Kawasaki Disease. It might have been 10 or 15 years since you first had Kawasaki Disease. Back then, Kawasaki Disease was both less well known and not as well understood. Because Kawasaki Disease needs urgent treatment for the best chances of a good recovery, our charity, Societi Foundation – the U.K. Foundation for Kawasaki Disease is dedicated to raising awareness – so that children can get the rapid treatment they need.
Ok – so that’s the initial treatment. What else?
Well, if Kawasaki Disease caused heart damage, children, young people and adults affected often go on to need lifelong medication. The exact treatment needed depends on just how, and how much their heart was damaged.
Treatments include medicines which make blood clots less likely and so help reduce the risk of what doctors call “Major adverse cardiac events”. To you and me, that’s heart attacks. It’s this risk of major illness in later life for some people, who have severe heart damage, which makes Kawasaki Disease such a serious illness.
No, as yet there is no specific test to help doctors diagnose Kawasaki Disease when children are first ill. It’s just one of a long list of things which can make it difficult for doctors to diagnose it quickly.
The good news is that our fabulous UK doctors are working **right now** to find a test, so that in future, more children can be diagnosed quickly and treated fast – improving their chances of a good recovery.
Quite a lot!
About 1000 children a year are seen in hospital with Kawasaki Disease in the UK. Increasingly common, Kawasaki Disease is affecting more and more children and young people in the UK each year – the number of children with Kawasaki Disease has risen about fourfold over the last ten years. And we don’t know why!
But that’s only part of the story. Because Kawasaki Disease has lifelong effects for many people, today there are thousands of children, young people like you and adults too, in the UK, who have Kawasaki Disease.
About a thousand children every year in the UK are admitted to hospital with Kawasaki Disease.
When thinking about when children are first ill with Kawasaki Disease, the illness mostly affects young children. So – you are quite likely to have been five years old or younger, when first poorly with Kawasaki Disease – because about three quarters of all children who have it are aged 5 or less. But it can affect any age group – so a quarter of you reading the page would have been older when first poorly! How old were you when you got it – do you know? 🙂
And because the damage it can cause to children’s hearts can be lifelong, thousands of children, young people and adults are affected in the UK today by Kawasaki Disease.
You’re not on your own!
It’s quite likely that at some point a doctor has said to you or your parents “Kawasaki Disease is really rare…” That might have made you – or your family – feel like you were going through this pretty much on your own. Well, we’re here to tell you you’re not! Because you’re part of a growing group. Kawasaki Disease is increasingly common – we point this out to doctors all the time! It isn’t rare any more! And if it helps, there’s lots of ways you can get connected to others who’ve been through Kawasaki Disease too. Check out the My Connections page!
Having Kawasaki Disease more than once is very, very unusual! But you know what – it can happen very occasionally. Only about 1 in 500 or maybe 1 in 1,000 children diagnosed with Kawasaki Disease go on to get it again. There’s not a great deal of research with big groups on this but doctors who have seen thousands of patients say that true recurrence (actually getting Kawasaki Disease again) is extremely rare perhaps 1 in 3,000 patients. So we think this is not something to worry about!
Unlike some other illnesses where children develop immunity or resistance to getting it again, this doesn’t happen in Kawasaki Disease.
Immunity? What’s that?
OK – let’s think about chicken pox for a minute – which you’ve probably had! If you have had chicken pox, it’s pretty sure you won’t get it again. Why? Because your immune system is clever and ‘remembers’ when it you had it the first time and made special cells to fight it off (and you got better!) Your immune system now has this memory of what to do and the cells it beat chicken pox with last time, so it knows how to fight it, if it sees the chicken pox germ again. Clever eh? We think so…. And that’s what’s meant by ‘immunity’.
This clever stuff with your immune system works with lots of germs like viruses and bacteria. We don’t know what causes Kawasaki Disease – what we do know though is that there’s no immunity built up from a first Kawasaki Disease illness.
YES YOU CAN!! Kawasaki Disease is no reason to avoid exercise! Keeping active and doing regular exercise you enjoy is even more important for you in fact.
But you’ll already know that it’s important that we all exercise regularly! Keeping our bodies fit and strong is important – but there’s lots of other reasons to exercise – like the great way exercise helps reduce stress and supports good mental health too. If you have heart damage from Kawasaki Disease, keeping fit and healthy – including being a healthy weight, is especially important.
Regular exercise improves heart health (you’ll have heard of ‘cardio exercise’ we’re sure!) – and it can help you maintain a healthy blood pressure, healthy levels of fats like cholesterol and help control blood sugar levels. We’re worried we’re straying into jargon here….. eeek – but what we’re trying to say is that exercise is a GOOD thing!
Got long term heart damage?
If you have severe heart damage from Kawasaki Disease which means you take anticoagulants (medicines which thin your blood to stop blood clots) your doctor will have talked to you about any limits you might have on doing things like contact sports (such as rugby). If you feel you’d like extra guidance on this, speak to your usual doctor the next time you see them or contact your GP.
We find it’s a great idea to make a note of any questions you have for your doctor. That way you can remember them at your next appointment. Why not pop a note on your phone! Especially if it’s going to be a while before you see them again – sorted!
Well. Perhaps it goes without saying – but this is an answer for the girls!
If you had Kawasaki Disease and made a good recovery without lasting heart damage, it’s still worthwhile mentioning Kawasaki Disease to your doctor if you’re thinking about getting pregnant. The doctor will ask about your “medical history” (that’s everything related to any illnesses and injuries since you were born!) Do let them know you had Kawasaki Disease, in just the same way that you’d tell them if you’d had an operation in the past, or are allergic to any medicines. They will give you advice and information. Research suggests it’s unlikely you’ll need to take any extra precautions or need any extra care but do mention Kawasaki Disease to your doctor and later on, to your midwife, so that they are aware.
If you have lasting heart damage from Kawasaki Disease, you should talk to your doctor and they will decide with you on whether you will need extra care if you plan to have a child in the future. If you are planning a pregnancy or find yourself pregnant, ask your doctor whether there are any extra precautions that might need to be taken to help you through pregnancy and child birth. Your usual doctor will be able to give you specialist advice based on your individual circumstances.
If you have severe heart damage, your doctor has probably already talked to you about this – but if not, you can raise it with them. Take your phone into your next appointment and show them this page if that helps!
Taking regular medicines? This bit is for YOU…
There are some medicines which shouldn’t be taken when you’re pregnant. So it’s a really good idea to plan things if you’re thinking about getting pregnant – start with a conversation with your doctor. Sounds weird – but it’s actually really important! You might need to change your medicines before getting pregnant – and they’ll want to chat through that, and other stuff too – for sure. So pop along to see your doctor if pregnancy is something you’re thinking about.
You may plan to travel to different countries in the future and want to know if there is anything you should think about if you have Kawasaki Disease.
Travelling to far off places isn’t off limits because you have Kawasaki Disease!
If you have coronary artery aneurysms or other heart damage (such as lasting dilatations – which are wider bits of your coronary arteries) because of Kawasaki Disease, there are few things you should think about if you plan to go travelling.
Regular medicines? Let’s get organised!
Firstly, make sure to take enough of any regular medication that you normally take with you when you travel. You might need to speak to your GP if additional prescriptions are needed – if you’re away for a while. Keep your medicines in the box they were given to you in by your chemist – that helps if anyone (at border control for example) has questions about pills or an injectable you are carrying. It’s handy to also have a list of your medications in case you lose them and need to get more.
Check out the destination!
You might want to check that your destination has the medical facilities you’ll need if you were to need a replacement prescription or if you needed medical care. Different countries across the world have very different healthcare systems, so you might want to do some research before you go. That includes making sure any prescription medicines you have are allowed in the places you plan to go — it might sound crackers….. but some drugs which can be prescribed in the UK are not approved in other places. So it’s always best to check.
Be sure to insure!
Make sure that you have the right medical insurance for your trip and be sure to tell your insurers about any health problems you have.
Speak to your doctor!
Your doctor will be able to give you advice and let you know what precautions, if any, you should take while travelling. As well as your usual doctor, you might want to speak to the person at your GP surgery who is the ‘go-to’ for all things to do with travel. Many surgeries, especially bigger ones, will have someone who specialises in travel related medical advice, vaccines and more. They will be able to give you great advice too – like, if you are travelling long distances over a long period of time, for instance, by plane, it’s a good idea to move around as much as you can. Stuff like this can really make the difference and allow you to have a great holiday!
Kawasaki Disease can sometimes cause some longer term effects in some people. Most of these resolve, or sort themselves out, within a year or two after first being ill. They include things like behaviour issues and dry skin.
Sometimes, re-peeling of skin on the fingertips and toes can happen occasionally, for quite a while after you were first ill with Kawasaki Disease. Doctors aren’t sure why this happens but do say it’s nothing to worry about, it’s not a sign you’ve got Kawasaki Disease again!
We have produced a little leaflet on longer term things – which explains a little more about this. You can download it below.
This short video stars (!!) two fab doctors who are *top* experts in Kawasaki Disease – Prof Rob Tulloh and Prof Paul Brogan. Rob and Paul talk about some of the possible longer term effects of Kawasaki Disease.
The coronary arteries are two important blood vessels. Why important? Well, it’s because they supply oxygen and nutrients to the heart muscle itself. That’s a pretty big, pretty important job then, hey?
Have a look at our pic here which shows the heart – including the left and right coronary arteries at a normal size. These arteries can be affected by damage caused by Kawasaki Disease, in some children.
An aneurysm is a swelling in an artery. The pic here shows a coronary artery aneurysm that could be caused by Kawasaki Disease. You can check out what a coronary artery is by scrolling on this page – it’s another question we’ve answered.
Aneurysms can vary in size. Doctors usually talk about them in 3 categories – small, medium or large/giant. Doctors also use something called a “z score” when talking about the size of an aneurysm – and they measure the aneurysms using an echocardiogram, or ultrasound scan of your heart. A Z-score is a technical term doctors use to describe the size of an artery compared to a normal one – there’s more on this topic (a full explanation we promise!) further down this page – together with a video you can watch.
Prof Rob Tulloh, top Kawasaki Disease expert, explains what a coronary artery aneurysm is in the video below too.
The size of any aneurysm is measured by a scan called an echocardiogram (an ultrasound scan of your heart). Doctors then compare the measurement they take from your scan, to an average, normal size artery. They have tables (or Apps!) which show them what someone’s arteries – of your height and weight would be without any damage.
The difference between this ‘average’ measurement and your measurement is then used to work out a “z score”. The z score helps doctors consistently assess how big or small an aneurysm is and will also help them decide about any treatment and medical care.
Normal arteries have a z-score of up to 2, a small aneurysm is from z = 2.5 to z = 5, a medium aneurysm is z = 5 to z = 10 and a giant aneurysm is z = more than 10 (or bigger than 8mm in diameter in anyone!)
Listen to Prof Rob’s explanation of a z score, in the video below. It’s tricky stuff – but because you’ll probably hear this phrase when you see your doctor we have included this explanation!
Blood is designed to clot!
It’s a really important process that stops us, when we are cut or injured, from excessive bleeding. Platelets (a certain type of blood cell) and proteins in your plasma (the liquid part of blood ) work together to stop bleeding by forming a clot over the injury. Your body’s natural repair mechanisms then get to work and repair the injury, underneath the clot – or scab.
This is clever stuff – when it happens to help us stop bleeding. But blood clots can happen sometimes when we don’t want them – and not in response to a cut or injury.
The same process that causes a clot over a cut can happen in your bloodstream, if blood slows down too much. In a coronary artery aneurysm, the artery is wider than it should be and blood can move more slowly – meaning it might start to think about forming a clot! So, when Kawasaki Disease causes coronary artery aneurysms, one of the things doctors look out for, is blood clots.
You might have heard this called thrombosis – which is a blood clot in a blood vessel, like an artery.
If you have one or more aneurysms, doctors will help lower your risk of any blood clots forming by giving you anticoagulants and antiplatelet medicines. Sometimes anticoagulants are referred to as ‘blood thinners’. These don’t actually make your blood thin, but instead, anticoagulants are specialist medicines used to reduce the likelihood of blood clots forming. Here are some links to find out more about two common anticoagulants used in treating Kawasaki Disease – warfarin and heparin.
Medication such as aspirin or clopidogrel are ‘antiplatelet’ – and make your platelets kind-of slippery (hey, that’s not the doctors definition but it explains it well!!) This means they don’t trigger the clotting process as easily. You can find out more about low dose aspirin on the NHS website here. And more here about Clopidigrel.
Ask the doc!
If you ever have any questions about your long term medication, or any medicines that your doctor has prescribed for you, just ask them when you see them next and they will be very happy to talk it through! You can always show them this page if that’s a good way of getting the conversation going.
Stenosis is something that your doctor may have talked to you about – especially if it is ten or more years since you first had Kawasaki Disease. Coronary artery stenosis means narrowing of the artery.
This can sometimes occur many years after having initially had Kawasaki Disease. If you had severe heart damage from Kawasaki Disease you’ll probably be being regularly seen by a doctor who understands this – and who will be looking out for it when you have your regular scans and tests. They will be doing tests such as exercise tests, special scans such as MRI scans or even taking a picture of your coronary artery with a special test called an angiogram.
Everyone is different, so ask your doctor if you want to know more information – and do ask if this is something your doctor is keeping an eye on in your case. If this hasn’t come up in your conversations – show your doctor this page and ask them to explain whether this might in future affect you. Remember, everyone is different and your doctor will be able to talk to you about your particular circumstances.