Let's move on to herpes number 3,
varicella-zoster virus, the
cause of chicken pox,
Transmission of this virus,
again, as with others,
can be through respiratory, meaning
sneezing, respiratory droplets,
but also an especially close
contact with active lesions.
Prevention for the varicella virus
is via a very active vaccine.
It's live, but attenuated.
It's administered in childhood beginning
at 12-15 months of life,
and a booster is given at
around age 4-5 years.
There now is a even higher potency
zoster virus vaccine for adults
to try and prevent the reactivation
that we'll talk about very shortly.
Initial infection with varicella-zoster virus
also hits the mucoepithelial cells.
You see a recurring target here
with the first 3 viruses,
and then it is spread through the reticulo-
endothelial system or bloodstream
throughout the body.
So rather than being a focal
target as we talked about with
the first 2 herpes viruses,
this one actually can spread throughout
a viremia per sorts,
and then any and all mucoepithelial cells
throughout the body can be affected.
For the first several days, one develops
as these virally-infected cells
go through lysis.
And then we get chicken pox,
the actual varicella
related to reactivated or activation
of the lytic lesions.
The latency with varicella-zoster virus is in
the dorsal route or trigeminal ganglia,
which is important when reactivation
occurs causing shingles
because that will occur in a specific
dermatomal distribution of the
trigeminal ganglia or the dorsal
root nerve focus
where the latency occurred.
So, let's compare and contrast the 2
diseases associated with
First, the incubation.
Chicken pox, during the incubation
period is 3-7 days,
during which time the patient
may be asymptomatic.
But toward the end of that time,
they'll develop typical viral,
So, fever, some sore throat, a cough, "Oh,
I think I'm coming down with something,"
coryza, so we can have some runny nose.
Basically, they may think they
either have the flu
or because of the sore throat, they
may think they have a strep throat.
Patients who are about to activate shingles,
sometimes will simply only feel tingling
right prior to the eruption of the legions
in that dermatome distribution.
However, they may also have a short-lived
Again, fever, cough, sore throat, rhinorrhea,
and sometimes, they'll have cervical adenitis.
Chicken pox lesions, again,
coming after a complete total
will be anywhere and everywhere.
Most often, they start up at the head.
In fact, the pearl for those of you
who enter pediatrics,
the place to look for a chicken
pox lesion is behind the ear.
Many times, those lesions hide there,
certainly up in the scalp area
covered by hair.
And then you may see them very rapidly,
over the course of a day,
erupt sort of throughout the body, but
from head down to toe.
Many times, they'll start centrally and then
they'll move out peripherally to
the arms, the legs, etc.
Shingles, again, is a dermatomal distribution,
very often seen on the face, many
times on the chest,
sometimes toward the back.
It's rare to actually have a purely
trigeminal nerve reactivation.
The progression for chicken pox.
One will see these lesions
heal, but in different stages, and so,
many times the patients seek care after
the first eruption of lesions has occurred,
and you have to distinguish
a chicken pox case from some of the
other blistering viral illnesses.
The key here is to find vesicles in
different stages of healing.
So you may see an early macule, you
may see a papule, you may see
a vesicle with that clear, clouded
fluid at the top.
You may see it already start to crust and
look kind of like a bacterial pustule,
or you may see a, sort of, hemorrhagic
which is to the final stages of recovery.
In shingles, the lesions are very painful.
They're almost like a painful itching.
It's a deep, burning itch.
And the lesions themselves
will be in a dermatomal distribution,
but look more hemorrhagic than
they do with the chicken pox.
So, here we have description and
pictures of the lesions.
So on the lower left side, the image
shows typical varicella
chicken pox lesions in differing stages.
The classic description, and you'll see
this historically as well as today,
of a chicken pox lesion at
its primary stage is
"dew drop on a rose petal."
A drop of dew, clear fluid dew
on a rose petal.
It's beautiful, except that itches
like you wouldn't believe.
On the right lower part of the slide,
you see a shingles activation in a
dermatomal distribution, right?
You can see that specifically in
just 1 part of the face.
It's on only 1 side of the face
If you see lesions like that crossing
the midline, meaning
both sides of the body, that is
not going to be shingles.
That'll be some other disease process.