Idiopathic aphthous ulcer

color=black]Recurrent aphthous stomatitis (RAS)
Idiopathic aphthous ulcer[/b][/b][/b][/b]

RAS is a very common condition which typically
starts in childhood or adolescence and presents
with multiple recurrent small, round or ovoid
ulcers with circumscribed margins. erythematous
haloes, and yellow or grey floors

RAS affects at least 20% of the population,
with the highest prevalence in higher socio-economic
classes.


Aetiopathogenesis

Immune mechanisms appear at play in a person
with a genetic predisposition to oral ulceration.
Agenetic predisposition is present, and there is a
positive family history. Immunological factors are also involved, with T helper cells predominating in the RAS lesions early on, along with some natural
killer (NK) cells. Cytotoxic cells then appear in the lesions and there is evidence for an antibody dependent cellular cytotoxicity (ADCC) reaction. It now seems likely therefore that a minor degree ofimmunological dysregulation underlies aphthae.

RAS may be a group of disorders of differentpathogeneses.
Cross-reacting antigens between the oral mucosa and microorganisms may be the initiators, but attempts to implicate a variety of bacteria or viruses have failed





.
Predisposing factors

Most people who suffer from RAS are otherwise
apparently completely well. In a few, predisposing
factors may be identifiable, or suspected.
These include:

1. Stress: underlies RAS in many cases. RAS are
typically worse at examination times.

2. Trauma: biting the mucosa, and dental
appliances may lead to some aphthae.

3. Haematinic deficiency (deficiencies of iron,
folic acid (folate) or vitamin B12) in up to 20%
of patients.

4. Sodium lauryl sulphate (SLS), a detergent in
some oral healthcare products may produce
oral ulceration.

5. Cessation of smoking: may precipitate or
aggravate RAS.

6. Gastrointestinal disorders particularly coeliac
disease (gluten-sensitive enteropathy) and
Crohn’s disease in about 3% of patients.

7. Endocrine factors in some women whose RAS
are clearly related to the fall in progestogen
level in the luteal phase of their menstrual cycle.

8. Immune deficiency: ulcers similar to RAS may
be seen in HIV and other immune defects.

9. Food allergies: underlie RAS rarely.

Clinical features

There are three main clinical types of RAS,
though the significance of these distinctions

1. Minor aphthous ulcers (Mikulicz Ulcer)

occur mainly in the 10 to 40-year-old age group,
often cause minimal symptoms, and are small round or
ovoid ulcers 2-4 mm in diameter.
The ulcer floor is initially yellowish but assumes a greyish hue as healing and epithelialisation proceeds.
They are surrounded by an erythematous halo and some oedema,
and are found mainly on the non-keratinised
mobile mucosa of the lips, cheeks, floor of the mouth, sulci or ventrum of the tongue.
They are only uncommonly seen on the keratinised
mucosa of the palate or dorsum of the tongue
and occur in groups of only a few ulcers (one to six) at a time.
They heal in seven to 10 days,
and recur at intervals of one to four months leaving little or no evidence of scarring

2. Major aphthous ulcers (Sutton’s Ulcers)

periadenitis mucosa necrotica recurrens
(PMNR)are larger, of longer duration, of more frequent recurrence, and
often more painful than minor ulcers.
are round or ovoid like minor ulcers, but they are larger and associated with surrounding oedema and can reach a large size, usually
about 1 cm in diameter or even larger.
They are found on any area of the oral mucosa,
including the keratinised dorsum of the tongue or palate, occur in groups of only a few ulcers (one to six) at one time and heal slowly
over 10 to 40 days.
They recur extremely frequently
it may heal with scarring
.
3. Herpetiform Ulceration (HU)

is found in a slightly older age group than the other forms
of RAS and are found mainly in females.
They begin with vesiculation which passes rapidly
into multiple minute pinhead-sized discrete ulcers
which involve any oral site including the keratinised mucosa.
They increase in size and coalesce to leave large round ragged ulcers, which heal in 10 days or longer, are often extremely painful and recur
so frequently that ulceration may be virtually continuous.


Diagnosis

Specific tests are unavailable, so the diagnosis
must be made on history and clinical features alone.

Investigation

to exclude the systemic disorders
Full blood count
Haematinics
Ferritin
Folate
Vitamin B12
Screen for coeliac disease
Biopsy is rarely indicated, and only when a different
diagnosis is suspected.


Management

Other similar disorders such as Behcet’s syndrome
must be ruled out.
Predisposing factors should then be corrected. Fortunately,
measures should be taken to relieve symptoms,
correct reversible causes (haematological
disorder, trauma) and reduce ulcer duration.
Maintain good oral hygiene
Chlorhexidine or triclosan mouthwashes may
help.

systemic steroids such as prednisilone in
doses of 20-40mg daily have shown promise


Topical corticosteroids can usually control symptoms
There is a spectrum of topical anti-inflammatory
agents that may help in the management of RAS.
Common preparations used include the following, four times daily:
• Weak potency corticosteroids topical hydrocortisone
hemisuccinate pellets (Corlan), 2.5 mg
or
• Medium potency steroids - topical triamcinolone
acetonide in carboxymethyl cellulose paste
(Adcortyl in orabase), betamethasone
or
• Higher potency topical corticosteroids (eg . beclometasone)

The major concern is adrenal suppression
with long-term and/or repeated application or systemic taken.

Topical tetracycline (eg doxycycline), or
tetracycline plus nicotinamide may provide
relief and reduce ulcer duration, but should be
avoided in children under 12 who might ingest
the tetracycline and develop tooth staining.

If RAS fails to respond to these measures, systemic immunomodulators may be required, under specialist supervision.

This topic from
My lovely reference
C. Scully1 and D. H. Felix2 . My note. and
BRITISH DENTAL JOURNAL VOLUME 200 NO. 2 JAN 28 2006