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Candidal Leukoplakia
(Chronic Hyperplastic Candidosis /
Candidal Epithelial Hyperplasia)
Chronic Hyperplastic Candidiasis or Candidal
Leukoplakia
is a persistent white lesion, characterised
by the increased production of a protein,
keratin
(
parakeratosis) and chronic intra-epithelial
inflammation
with fungal (Thrush) hyphæ invading the
superficial layers of the
epithelium (top-most layer of
the skin).
Photo of Candidal Leukoplakia (of the R Commissure)
B&W Photo of Candidal Leukoplakia (of the R Commissure)
What is Candidal Leukoplakia?

Chronic oral candidosis produces a tough, adherent, white
plaque (
leukoplakia), distinguishable only by biopsy from
other
leukoplakias.

Chronic hyperplastic candidiasis or candidal leukoplakia
is a persistent white lesion, characterised
histologically
(under the microscope) by
parakeratosis (increased keratin
production) and
chronic intra-epithelial (within skin cells)
inflammation with fungal hyphæ (shape of fungus) invading
the superficial layers of the
epithelium (skin).

Candidal leukoplakia is an uncommon condition found in
adults.


What is the Cause of Candidal Leukoplakia?

The epithelium of some leukoplakias is invaded by
Candida hyphæ but it is unclear whether the yeasts are
secondary invaders or are causally involved in the
development / transformation of
leukoplakia.

  • The cellular changes often include hyperplasia;
    however, cellular changes can occur that range from
    mild dysplasia to invasive carcinoma.
  • C. albicans is the species of fungus that is most
    commonly found in association with candidal
    leukoplakia.
  • The Candida biotypes associated with candidal
    leukoplakia differ from those isolated from normal
    mouths.

Candidal leukoplakia may be predisposed to in a minority
of patients by:

  • smoking
  • iron and folate deficiencies
  • defective cell-mediated immunity
  • blood group secretor status.


What are the signs and symptoms?

Adults, typically males of middle age or over, are affected.
The usual sites are the dorsum of the tongue and the post-
commissural buccal mucosa (see photos).  The plaque is variable
in thickness and rough / irregular in texture or nodular with an
erythematous background ('speckled').  Angular stomatitis may be
associated, is sometimes continuous with
intra-oral plaques and
suggests the
candidal nature of the lesion.

Candidal leukoplakias are chronic, discrete, raised lesions that
vary from small, palpable, translucent, whitish areas to large,
dense, opaque plaques, hard and rough to the touch (plaque-like
lesions).  
Homogeneous areas or speckled areas can be seen,
which do not rub off (
nodular lesions).

Candidal leukoplakias are non-homogeneousspeckled'
leukoplakias in up to 50%.

Candidal leukoplakias usually occur on the buccal mucosa on one
or both sides, mainly just inside the
commissure, less often on the
tongue.


How Is It Diagnosed?

Unlike Thrush (weblink), the plaque cannot be wiped off but
fragments can be detached by firm scraping.  Under the
microscope,
Candidal hyphæ are seen in amongst the epithelial
cells
.  The hyphæ (photo) are seen growing (as in Thrush) through
the full thickness of the
keratin to the prickle cell layer of the skin,
where the inflammatory cells tend to be more concentrated.

Electron microscopy shows
Candida albicans to be an intra-
cellular parasite
growing within the epithelial cytoplasm.

Induction of epithelial proliferation by C. albicans infection has
been demonstrated experimentally.  
Dysplasia (definition) may be
present, especially in
speckled lesions.

Candidal leukoplakia should be biopsied both to:

  • distinguish it from other non-candidal lesions
  • examine for possible dysplasia.


How is it treated?

After confirmation of the diagnosis by histology, treatment should
be with a systemic anti-fungal drug such as
fluconazole (this may
have to be continued for several months).  Other factors likely to
perpetuate
candidal infection should be controlled.

Stopping the patient from smoking and elimination of
candidal
infection from under an upper denture are important.  Any iron
deficiency should also be treated.

Excision of
candidal plaque alone is of little value, as the infection
can recur in the same site even after skin grafting.  Vigorous anti-
fungal therapy is therefore essential but sometimes some residual
(uninfected) plaque may persist after treatment and lesions often
recur and require long-term intermittent anti-fungal therapy.


Prognosis

The potential for malignant change exists.  The level of risk is
controversial but low (9% to 40% of
candidal leukoplakias may
develop into carcinomas [cancers]).

Factors influencing the prognosis may include:

  • risk factors, such as tobacco and alcohol use
  • whether the lesion is speckled (more dangerous) or
    homogeneous
  • the presence (more dangerous) and degree of epithelial
    dysplasia

In order to improve the prognosis:

  • Tobacco and alcohol habits should be stopped.
  • Anti-fungals should be used.  The lesions of candidal
    leukoplakia may prove poorly responsive to polyene anti-
    fungal drugs (such as ) and, in some cases, respond only to
    systemic fluconazole.
  • Excision is indicated if there is more than mild dysplasia.
  • The patient should be fully informed about the condition and
    reviewed regularly.



Useful Websites:

Critical Reviews in Oral Biology & Medicine

Useful Articles:

Postgrad Med J 2002.  Oral Candidiasis.
Last Updated 18th August 2010