Oral Medicine/Pathology

“The mouth is a mirror of health or disease, a sentinel or early warning system. As the gateway to the body, the mouth is challenged by a constant barrage of invaders – bacteria, viruses, parasites, fungi. Many systemic diseases such as diabetes, arthritis, osteoporosis and AIDS, as well as therapies for systemic diseases, can affect oral tissues.” – U. S. Surgeon General’s Report

This section on oral medicine and pathology deals with common infections of the mouth other than caries or periodontal disease.

It is divided into five topics:

A. Oral infections: Bacterial, viral and fungal
B. Blister lesions of the mouth
C. Pigmented (dark-colored) lesions of the mouth
D. White patches in the mouth
E. Pre-cancerous lesions in the mouth

A. Oral infections

1. What bacterial mouth infections (other than tooth decay and gum disease) should I be aware of?

  • Oral bacterial infections other than tooth decay and gum disease are rare, but can occur:
    • Scarlet Fever can affect the tongue or cheeks.
      A typically strawberry or raspberry colored tongue is seen at an early stage.
      The rest of the mouth and throat are also affected.
    • Syphilis and Tuberculosis can also affect the mouth.

2. How are bacterial infections treated?

  • Your doctor will examine you, carry out tests if necessary, and will prescribe an antibiotic to cure the infection.

3. What viral infections can affect the mouth?

  • Herpes Simplex
    • This causes Oral Herpes, which affects from 50-60% of HIV patients.
    • It is a chronic infection, with widespread painful ulcers.
    • The ulcers are white with red borders.
    • Medications may allow it to disappear for a time, but it will re-appear.
    • It is spread by intimate physical contact.
    • Infants can acquire it from their mothers during pregnancy or birth.
    • In people with immune deficiencies it is particularly severe, and prolonged treatment may be needed.
  • Cold Sores, found on the lip, are also caused by a herpes virus.
  • Measles may appear in the mouth as little white spots with a red border.
  • Chicken Pox blisters are also found in the mouth.
  • Ulcers occurring during glandular fever (Infectious Mononucleosis) may resemble herpes ulcers.

4. How are viral infections treated?

  • There is no cure for a viral infection, and so the symptoms need to be treated.
    • This is done by using mouth-rinses, and applying topical anesthetics and protective ointments to the ulcers.
    • In most cases the viral infection lasts for 10-14 days.

5. What fungal infections can affect the mouth?

  • Thrush, also called candidiasis, is the most common fungal mouth infection.
    It appears as a white patch, which can easily be stripped off to leave a red, bloody area.

6. How is thrush (candidiasis) treated?

  • It is treated with an antibiotic and a mild antiseptic mouth rinse will usually be prescribed.
  • Tooth brushes should be discarded after each use to prevent re-infection.

7. What is a canker sore or aphthous ulcer?

  • This is a painful ulcer that can vary in size and appears singly or in groups.
    • The exact cause is unknown, but stress and viruses probably play a role.
    • These rounded, painful, shallow ulcers recur at intervals of a few days to a few months
    • The ulcers are less than 5 mm. in diameter.
    • They have a grey/white centre, with a red, inflamed border.
    • The lips, cheeks and the floor of the mouth are affected.
    • The healing period is about 10-14 days.

8. How are cankers treated?

  • In most instances these conditions get better spontaneously in 10-14 days.
    • Protective ointments and pain relievers are applied directly to the ulcers. They are usually the only pain relief that is needed.
    • Occasionally the doctor may prescribe steroids.
    • Chlorohexidine mouthwashes can have a beneficial effect.

B. Blister lesions of the mouth

1. What are blister-type lesions?

  • These are blisters or vesicles of varying size, found on the inner surfaces of the cheeks.
    They sometimes rupture (pop) leaving raw, open wounds

2. What is the difference between a vesicle and bulla?

  • Vesicles are small, only a few millimeters in size.
    Bullae can be considerably larger.
    Both are blisters.

3. What kinds of blisters are most commonly found in the mouth?

Blister lesions are not common. The following are some that may occur:

  • Pemphigus is a chronic skin disease, which also appears in the mouth.
    • It is related to immune system problems, and appears in middle age.
    • It requires specialist treatment using steroid medication.
  • Pemphigoid is not associated with skin problems.
    • It can also affect the eyes
    • This is a common inflammatory lesion. The erosive or ulcerated form can be pre-cancerous.
    • It needs treatment with steroids, by a specialist.
  • Lichen Planus
    • This condition affects adult women more commonly than men.
    • It is mostly seen on the inner surface of the cheek in a lacy pattern of white raised areas.
    • The erosive or ulcerated form of this condition is rare, but can be pre-cancerous.
    • It is usually a benign condition and is not the same as leukoplakia.
  • Erythema Multiforme
    • This appears on the skin as well as in the mouth.
    • It is related to certain drugs and immune system problems, and is most commonly found in young men.
    • The symptoms need to be treated by a specialist, but the cause is often difficult to find.

C. Pigmented (dark-coloured) lesions of the mouth

All pigmented (dark-coloured) areas found in your mouth must be brought to the attention of your dentist.

1. What are the dark brown to black stains on my gums?

  • These dark, pigmented areas are most commonly related to melanin, the dark pigment responsible for dark skin.
    This melanin is also found in the gums of dark skinned people.

2. Could my amalgam fillings have caused the black stains on my gums?

  • When amalgam accidentally gets into the gums, it causes a black stain called an amalgam tattoo.
    This is the most common form of dark, localized pigmentation.

3. Can amalgam tattoos be removed?

  • Yes, they can be surgically removed.

4. Are the little black moles in my mouth dangerous?

  • These darkly pigmented areas (called “Naevi”) are usually harmless, but should be checked by a doctor.

5. Do malignant melanomas occur in the mouth?

  • They are relatively rare but life threatening.
    They are generally very dark and irregular in outline, and can grow rapidly.

6. I have a dark bluish-black spot where I bit my lip. What is it?

  • This is a bruise or haematoma.
    It will probably disappear soon.

7. What are other causes of pigmentation in the mouth?

  • Foods, drugs, some blood disorders, and endocrine problems may cause oral pigmentation.

8. What could turn a tongue black and hairy-looking?

  • It sounds terrible, but this is usually a benign condition, which will eventually go away.
    It may be related to antibiotic treatment.

D. White patches in the mouth

1. Could the white patches in my mouth be caused by smoking?

  • White patches on the palate, tongue or the inside of the cheeks can be caused by smoking, particularly pipe smoking.
    • This condition is called smokers’ keratosis.
    • The patches may disappear if you give up smoking.
    • They may, however, also be pre-cancerous.

2. What can be done about the numerous red spots on a grey or white base on my palate?

  • Give up smoking cigarettes, and the spots or papules, will go away.
    This condition is called stomatitis nicotina, and is caused by cigarette smoking.

3. What is leukoplakia?

  • Leukoplakia presents as white patches in the mouth that cannot be wiped off.
    They may be present on the inside of the cheeks, on the floor of the mouth, or under the tongue.
    Some of these patches may become cancerous.

4. What are the white patches found in the mouths of tobacco chewers?

  • This is a form of leukoplakia caused by chewing tobacco that is kept between the cheek and gum.
    It can be pre-cancerous.

5. What is lichen planus?

  • This condition affects adult women more commonly than men.
    • It is mostly seen on the inner surface of the cheek in a lacy pattern of white raised areas.
    • The erosive or ulcerated form of this condition is rare, but can be pre-cancerous.
    • It is usually a benign condition and is not the same as leukoplakia.

6. What is the white spongy patch sometimes seen on the inside of the cheek?

  • This is called a White Spongy Naevus.
    • It is an inherited condition.
    • It is benign and usually needs no treatment.

7. Are there any other white lesions that can occur?

  • White lesions can be caused by:
    • Chemical burns from substances such as aspirin.
    • Infections such as thrush.
    • Some diseases that affect the entire body may cause white lesions

8. Should I worry about white patches in my mouth?

  • All white lesions in the mouth must be examined by your dentist or doctor.
    • The sooner you have a white patch attended to the less you will have to worry about.
    • A neglected problem may not go away and may be cancerous.

E. Pre-cancerous lesions in the mouth

1. Can oral conditions become cancerous?

  • It is very difficult, if not impossible, to predict which lesions will become malignant.
    Some oral conditions do have an increased risk of becoming cancerous.
    These include:

    • The white patches of leukoplakia.
    • Erosive lichen planus.
    • Submucous fibrosis.

2. How are pre-cancerous conditions treated?

  • Specialists monitor these pre-cancerous conditions to see if there are any important changes in the cells.
    Sometimes the pre-cancerous lesion is removed surgically.

Important note for this section on oral medicine and pathology:

  • It is essential to see you dentist regularly twice a year for a check-up, and immediately after any problems arise.
  • All conditions in this section should be diagnosed and treated by a dentist or medical specialist, not by you.

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