This is part two of the talk.
This is Dr. Nikitakis talking about
presenting as soreness and ulcers,
and we will now focus on diseases showing
occasional subepithelial blister formation
which is accompanied
by basal cell destruction.
These diseases include
primarily lichen planus,
a common oral disease.
Lichen planus has to be differentiated
from other similar looking diseases
as well as from lupus erythematosus.
We will talk about lichen planus,
we will briefly mention
some lichenoid reactions,
and the entity called
chronic ulcerative stomatitis,
while the entity called
graft-versus-host disease or GVHD
will be covered in a different lecture
of the same series.
Lichen planus is one of the most
important oral diseases
because it is quite common.
It can be classified
as an immunologically-mediated
the etiology of which
is not very well understood.
However, we believe that lichen planus
is associated with a genetic predisposition,
and for some patients,
there may be association
with emotional stress
that can exacerbate disease.
In these diagrams, we see some elements
of the pathogenesis of the disorder
where some antigens in the epithelium
are detected by Langerhans
and other antigen presenting cells.
These antigens are presented
to the T lymphocytes
and the T-cell reaction is Maimed.
On the right side, we see the various T cells
such as CD4+ and CD8+ are accumulating
in the basement membrane zone,
in the subepithelial connective tissue,
or even within the epithelium
causing destruction and necrosis
of the basal cell layer.