• The lesions appear singly or in
• on the nonkeratinized oral
mucosa, particularly the soft
palate, bucolabial mucosa, floor
of the mouth, and lateral borders
of the tongue.
Nonkeratinized squamous epithelium covers the soft palate,
inner lips, inner cheeks, and the floor of the mouth, and ventral
surface of the tongue. Keratinized squamous epithelium is
present in the attached gingiva and hard palate as well as areas
of the dorsal surface of the tongue.
Small (< 5mm),
Rounded, superficial erosions,
Covered with gray-white exudate,
Having an erythematous rim.
• The canker sores are self-limited
and usually resolved within a few
weeks, but they may
in the same or different location
in the oral cavity.
• ‘Extremely common infection caused by
• Transmitted from person to person by
• By middle life over ¾ of the population
have been infected.
• They occur most often on
the lips or about the nasal
orfices and are well known
as cold sores or fever
blisters. They soon rupture,
leaving shallow, painful
ulcers that heal within a
few weeks, but
recurrences are common.
• In most adults the primary
infection is asymptomatic, but
the virus persists in a
dormant state within
ganglia about the mouth
• With reactivation of the virus
(which may be caused by
fever, sun or cold
exposure, respiratory tract
infection, trauma), solitary or
containing clear fluid appear.
Entry by skin or mucous membranes
lysis of cells
• The vesicles begin as intraepithelial focus of
intercellular and intracellular EDEMA.
• The infected cells become BALLONED and develop
intranuclear acidophilic viral INCLUSIONS.
Sometimes adjacent cells fuse to form GIANT CELLS
• Necrosis of the infected cells and the
focal collections of edema fluid
account for the INTRAEPITHELIAL VESICLES
• Identification of the inclusion-bearing cells or
polykaryons in smears of blisters fluid
constitutes the diagnostic Tzanck test for
• In 10-20% of those with this conditionparticularly in the immunocompromised– a
more virulent disseminated eruption
develops, producing multiple vesicles
throughout the oral cavity, including the
gingiva and pharynx (herpetic
In particularly severe
cases, viremia may seed
the brain (causing
encephalitis) or produce
HSV type 1 may localize in conjuntivae
(Keratoconjunctivitis) and the
esophagus when a NG tube is
introduced though an infected oral
As a result of changes in sexual
practices, genital herpes produced by
HSV type 2 (the agent of herpes
genitalis) is increasingly seen in the
oral cavity, producing vesicles in the
• Candida albicans is a normal
inhabitant of the oral cavity found
in 30-40% of the population; it
causes disease only when there is
impairment of the
• Pseudomembranous candidiasis
(thrush, moniliasis) is the most
common fungal infection of the
oral cavity and is particularly
common among persons rendered
vulnerable by diabetes mellitus,
immunodeficiency, or debilitating
illnesses such as disseminated
cancer. Persons with the acquired
immunodeficiency (AIDS) are at
An adherent white, curd like,
circumscribed PLAQUE anywhere
within the oral cavity.
The pseudomembrane can be
scraped off to reveal an
underlying granular erythematous
• The pseudomembrane is composed of a
myriad of fungal organisms
superficially attached to the underlying
• In milder infections there is minimal
• in severe cases the ENTIRE MUCOSA may
• Dissiminated candidiasis is a life
threatening infection that must be treated
AIDS & Kaposi Sarcoma
• AIDS is often associated with lesions in
the oral cavity.
• They may take the form of candidiasis,
herpetic vesicles, or some others microbial
infection (producing gingivitis or glossitis).
AIDS & Kaposi Sarcoma
• Hairy leukoplakia is an uncommon lesion seen
virtually only in persons infected with HIV.
• It consists of white confluent patches, anywhere
on the oral mucosa, that have a “hairy” or
corrugated surface resulting from marked
epithelial thickening.It is caused by Epstein-Barr
virus infection of epithelial cells. Occasionally, the
development of hairy leukoplakia calls attention to
the exitence of the underlying HIV infection.
AIDS & Kaposi Sarcoma
• More than 50% of individuals with Kaposi
sarcoma develop intraoral purpuric
discolorations or violaceous, raised, nodular
masses; sometimes this involvement
constitutes the presenting manifestation.
Kaposi sarcoma is a tumor caused
by human herpesvirus 8.