In this lecture we will discuss
This is commonly addressed
on multiple choice tests.
So Kawasaki's disease is a multisystem
inflammatory condition of medium
sized blood vessels.
The mechanism behind
Kawasaki disease is not at all understood.
Nobody understands why this happens.
That said, there are some significant
differences between Japanese and American
Kawasaki disease, that might shed
some light on the path of physiology.
The disease was discovered in Japan, hence
the Japanese name.
Retrospective studies have been used
to try and determine what was happening
when we saw children who presented
with coronary artery aneurysms.
They then looked at all
these children who had all these symptoms
prior to the development
of the coronary artery aneurysms,
and they put together a clinical criteria
for the diagnosis of the disease.
That said, the Japanese disease
and the American disease
are so different
that perhaps they are different diseases.
Children with Japanese Kawasaki
tend to get much sicker and are much
more likely to have giant aneurysms
that can be life threatening.
These two diseases are treated
differently on the two continents
and we will focus in this lecture
on American Kawasaki disease.
So Kawasaki is a common vasculitis
80% of children will have it before
five years of age.
However, a small percentage can have it
even later, even over the age of ten.
self-limited initial inflammatory stage
that ends about after 12
to 14 days of significant inflammation.
However, if untreated
during the inflammatory stage,
that child now has a risk
for development of coronary artery
which can absolutely be life threatening.
In children under one year of age
who have the disease,
they will have a worse prognosis
and be more likely
to develop the coronary artery aneurysm.
So let's go through the clinical criteria
for the diagnosis of this condition.
One way to remember it is crash and burn.
So burn first.
These patients need
at least five days of fever.
Now let's go through the crash part
of crash and burn.
Each letter in the word crash.
Stands for one of the five major criteria
for Kawasaki disease.
C is for conjunctivitis.
This is a limbic sparing
nonpareil and conjunctivitis
or is for rash any type of rash.
A is for add in apathy,
usually in the anterior cervical chain.
S is for strawberry tongue,
but realistically, it can also be dry
red cracked lips
any sort of mouth mucous membrane changes
and h is for hands and feet in particular.
Swelling, although peeling does
also count as a criteria
in that under one age group
who have fever for seven days.
And no other explanation for it.
So for a diagnosis of Kawasaki,
you need either four
or five of these criteria.
Plus the five days of fever, the crash,
four or five
and the burn, you need five days of fever.
So the fever should
be more than 37.5 degrees centigrade
for at least five days.
If the patient meets other criteria,
early treatment may be less effective.
And in general,
one key thing about the systemic symptoms
and this isn't a criteria,
but it definitely tips you over the edge
in these questionable cases.
Children with Kawasaki are irritable,
they don't want you to be near them.
They are really fussy and they feel much
better after their treatment.
Let's look at this conjunctivitis.
It'll look a little bit like this.
It's basically a non purulent
red eye, no pus, just red.
And the area around the limbic parts of
the iris is spared.
The redness is more peripheral,
so it's limbic sparing.
And patients may have some photophobia,
but that's not necessary
at all for the diagnosis.
changes include the strawberry tongue.
Can't really see it too well here,
but this child definitely also has dry,
red and cracked lips, which are positive
pneumonic for the condition.
The lymphadenopathy is usually unilateral.
It's usually in the anterior
cervical chain and they have to have one
node that's at least
1.5 centimeters large.
The rash is nonspecific
it's usually a macular popular
erythematosus rash that looks like
your typical viral exam them.
It usually involves the trunk the face,
the extremities or the diaper area,
the hands and feet condition,
maybe red or just swollen.
Sometimes a patient comes in on day
four of illness and the mom says, Oh yes,
three days ago her hands were swollen
and I just didn't do anything about it.
A historical report of one of these
counts in the criteria for this disease.
Here's an example of
the peeling of fingers that can happen
usually later in the syndrome.
Also, patients can get other symptoms
which don't define the disease.
But do happen and may tip you over
the edge in a questionable case.
Patients may develop an arthritis.
We may get lefties
because patient can have a hepatitis.
Check for it by ultrasound.
Usually cases will resolve on their own.
However, surgical consultation
may be indicated
So here's a typical picture
and it's a good picture to look at
when these symptoms typically happen
in the normal course of the illness.
From the top line,
you can see that the fever
will typically last more than five days.
It may last even to or weeks or longer,
but eventually untreated
that fever will resolve.
The other symptoms that we
use to define the conditions
such as the conjunctivitis.
The change in mucous membranes
or the cervical lymphadenopathy
tend to happen early in disease.
The rash perhaps a little bit later
and the extremity change
at first is swollen
and then later is peeling.
typically happen a little bit later
on, such as the gallbladder high drops
So radiologic studies
and lab studies can be helpful,
especially in a patient
who is a typical Kawasaki
Atypical Kawasaki is when patients meet
either two or three criteria,
and we need other findings to help justify
whether or not
we should be treating that patient.
Labs that are indicating
that something more significant
is going on include the ESR and the CRP
They may have an elevated white count.
Patients on CBC
may also have enormous acidic anemia.
This is consistent
with just an inflammatory process.
Same thing with their thrombosis ptosis,
which is a high platelet count.
Patients may have increased left vs
that is a sort of systemic hepatitis
from the inflammation.
One of the key things that shows up on
test frequently is sterile diarrhea.
When obtaining a urinalysis on a patient.
With this, we may notice that they have
increased white cells in their urine
and suspect a urinary tract infection
but nothing ever grows out.
One key, subtle point about the sterile
is it may be a urine arthritis
rather than a pile of nephritis.
So if a patient is Kath arised to obtain
the urine specimen, it may be missed.
These children should be bag urine
and a urine culture should not be sent
because bag urines have a higher false positive rate for a urinary tract infection.
Additionally, if for some reason
the child does get a spinal tap,
most do not.
A sterile CSF pleo ptosis is possible
just like the sterile PI area
Another key finding is low serum albumin.
They often have that as well.
So an echocardiogram
is the mainstay of watching
for these changes
in their in their coronary arteries.
And we're looking for coronary artery
The echo may be positive early,
but usually the coronary artery
aneurysms are a later finding.
We obtain an echo
around the time of diagnosis.
It's not a huge emergency,
but we'd like to get it done
in the first couple of days.
And the reason for that is not only
are we looking for
some rare signs
of involvement of the heart,
patients can get myocardial dysfunction
or a pericarditis,
or they can get very mild dilatation
or activation of their corner arteries.
But mostly we're getting the early echo
as a baseline
of their coronary arteries.
So that we can compare
their coronary arteries
on when they come back for follow visits.
And we're actually tracking
for the development of an aneurysm
Babies under six months of age
with seven days of fever
and no other symptoms
at all, meet a typical criteria
that is a special exception
because very young infants
with Kawasaki can present very typically
the management of Kawasaki's is something
you should be very familiar
with after their five days of fever.
And once they've met criteria, four
or five criteria
for the typical Kawasaki disease
or two or three criteria
with additional lab
findings and echo concerns,
we will proceed to give IVIG.
This is high dose IVIG,
which is two grams per
kilo, and it's given over many hours.
It's given slowly
because IVIG has side effects.
We worry about.
An example would be set shock.
Patients getting IVIG can have
significantly lower blood pressures
and go into shock.
So we're going to administer it
Keep in mind there are some side effects
of the IVIG that should concern you.
One of them is headache, and that's common
But another concerning one is fever.
And this is because we're using
a resolution of fever of the disease
as a way of checking to see
if the therapy is working.
If they continue to have fever.
We will wait typically a period
of about 36 hours
after the IVIG is completed
to check for fever
because an earlier fever
may just be from the IVIG itself.
we will give aspirin, we'll give high dose
aspirin while they're in the hospital
and in a febrile state.
And then once they're deferred
vest and ready to go home,
we will transition them to low dose
The aspirin is given early
as an anti-inflammatory
and later as a way to prevent clots
forming in the event that child does form
a coronary artery aneurysm.
There is some evidence
that the aspirin is of little benefit.
However, it's very unlikely
this is going to change in the future
because to do a study where you withheld
aspirin would be hard to pull off.
we will check these patients recurrently
over a two to six week period
every two to six weeks to make sure
they're no longer having any involvement
of their coronary arteries
or that they're having none at all,
or that if there is involvement
we're tracking that involvement.
These children will get routine follow up
echos until cleared by the cardiologist.
So that's my review of Kawasaki's disease.
Thanks for your time.