00:01
Here we have erythema migrans.
00:03
We want to make sure that you take a
second and you take a look at this picture
and it’s like you’re taking a dart
and you’re practicing --
dartboard.
00:14
In other words, you’re
going after the target.
00:17
This is a target lesion.
00:20
What happened?
If you go right –
Take a look at this a little bit closer.
00:22
I want you to go into the
middle of the target.
00:25
That’s where the Ixodes
tick burrowed, right?
Deep inside.
00:30
And when it did, it then
elicited or introduced
a bacteria or spirochete
called Borrelia burgdorferi.
00:37
Welcome to Lyme disease.
00:39
All right, so erythema migrans
or erythema chronicum migrans,
we call it a target lesion.
00:45
Pay attention to the description.
00:47
You have a central
area of erythema.
00:50
Think about target.
00:51
Surrounded by pallor.
00:54
Then surrounded by a perimeter
or ring of erythema.
00:58
And the cycle continues.
01:00
Target, target, target lesion.
01:02
It may be associated with fever and/or
arthralgia caused by Borrelia burgdorferi.
01:07
The name of the tick is Ixodes.
01:08
Remember with Lyme disease,
you’re up in northeast U.S.,
you were hunting deer for example,
and you end up developing or acquiring
the tick and then the bacteria.
01:19
Here’s my vector, the
Ixodes scapularis.
01:24
Management: Doxycycline.
01:28
And we have fifth disease.
01:29
This is erythema infectiosum.
01:32
Make sure that you’re
familiar with this.
01:34
Fever, coryza.
01:37
What ends up happening in
terms of your history?
It looks like there’s
a slapped cheek.
01:43
Fifth disease, think of it that way.
01:44
Take your hand, which
has five fingers,
slap my cheek.
01:49
Slapped cheek-like appearance.
01:52
Lacy, reticular rash on the trunk and extremities.
01:54
Take a look at this patient here
and you’ll notice on the back,
it's a lacy type of reticular –
What does reticular mean?
Networking.
02:03
Remember the reticular pattern
that we saw on chest x-ray
with interstitial lung disease?
The same thing, but this time,
we’re going to find this
being erythematous.
02:12
Now, the cause is --
memorize parvovirus B19,
a single stranded DNA.
02:19
No longer really infectious
once the rash appears.
02:23
Pregnant women exposed are at risk
of hydrops fetalis, unfortunately.
02:30
And may cause what’s known as
your transient aplastic anemia.
02:34
Why?
Because if you’re dealing a parvovirus B19,
there’s every possibility that there
is shutting down of your bone marrow,
resulting in a normocytic type of
aplastic or non-hemolytic type of anemia.
02:49
That, we’ll talked about plenty
when we deal with parvovirus B19
with either sickle cell
disease ands so forth.