Basic lesions in oral dermatology.
Basic lesions in oral dermatology.
TO : 2023- 2024
I – Introduction:
- In dermatology, the elementary lesion reflects a lesion process and allows a classification of the pathology based on these lesions.
- In the oral cavity, we can make a transposition of these dermatological lesions, except that they are quickly modified by saliva, gingival fluid, movements of the tongue and lips, etc.
Commonly, we distinguish between:
- Primary elementary lesions : reflecting the initial lesion process.
- Secondary elementary lesions: represent the evolution of this process.
Criteria to study:
- Identification of the lesion
- Layout and limits: round, oval, roundel, linear, etc.
- Flat, domed, pedunculated, sessile, acuminate,
- Size (encrypted)
- Color
- Surface anomaly
- Consistency
- Depth
- We distinguish between primary or primitive elementary lesions which correspond to the initial lesion process,
- And the secondary elementary lesions which represent the evolution of this primary process.
II. Histological reminder
- The oral cavity is entirely lined by a mucosa resting on the connective, muscular and bony planes. The mucosa consists of a lining epithelium resting on the lamina propria through a basement membrane.
1. The epithelium:
It is paved, stratified, keratinized or not depending on the location, it includes:
• A germinative cell base backed by the basal membrane (made up of cubic cells and melanocytes, this is the stratum germinatum)
• A Malpighian mucous body (stratum spinosum). The cells are larger and begin to flatten (this phenomenon becomes more pronounced as the cells migrate towards the surface.
• Granular layer (stratum granulosum) found in the keratinized mucosa area.
• Superficial horny layer (stratum corneum) which flakes off.
2. The chorion: Loose, richly vascularized connective tissue, containing:
• Accessory salivary glands
• Nerve endings
• Fibroblasts, Lymphocytes, plasma cells, monocytes and macrophages.
It is logical to deduce that there are several histological variations related to the topography and physiology of the oral mucosa.
o Masticatory mucosa: attached gingiva, hard palate; or the epithelium is keratinized
o Covering mucosa: cheeks, lips, ventral surface of the tongue, floor, soft palate or non-keratinized epithelium
o Specialized mucosa: dorsal surface of the tongue, keratinized, is provided with taste buds
III – primary lesions:
1-The macula:
Corresponds to a change in color of the mucous membrane without relief or infiltration.
This term includes:
- Erythema: Erythema: localized or diffuse redness that disappears under vitro pressure. It may be enanthema: mucous membrane location Or exanthema: cutaneous location.
- Vascular macule: vasodilation not disappearing under vitro pressure e.g.: angioma
- Purpuric macule: red spot that does not disappear with vitropression e.g. purpura
- Dyschromia: pigmentation defect.
2- the papule:
A papule is a raised, circumscribed, solid lesion that does not contain liquid. It is called a plaque when the diameter of the lesion exceeds 0.5 cm.
As for the macule. The papule can be single or multiple
Red, white, hyper or hypopigmented in color.
Leukoplakia plaques are an example of a papule.
3- nodule:
Slightly protruding, round or oval, deep, sometimes painful swelling.
Corresponds to a deep infiltration of the chorion by cellular proliferation.
eg: tumors.
An infiltration: is a sign of induration found on palpation and must be systematically looked for even if the lesion is flat, it first suggests a cancerous lesion.
4- gallbladder:
These are small intra-epithelial elevations containing a clear serous or hemorrhagic fluid. After rupture, they give way to superficial erosions.
The etiology is essentially viral.
A pustule is a superinfected vesicle filled with pus.
5- bubble:
Bullae are rounded or oval epithelial detachments of clear or hemorrhagic content. Their presence in the oral cavity is ephemeral due to the fragility of the roof of the bulla. Their rupture gives way to more or less deep ulcerations.
6- : Vegetation:
Papillomatous growths that have a cauliflower-like appearance.
7- keratoses: these are white lesions which may be flat or raised with a warty appearance.
Parakeratosis……..orthokeratosis.
8- Gum: bulky, solid protruding formation going through 4 stages (crudity, softening, fistulization, scarring)
9- The pustule: They are rarely observed, it is a circumscribed lifting of the skin or the mucous membrane and whose content is purulent.
10- Purpura: extravasation of blood outside the vessels of the skin or mucous membranes which can result in either petechiae (red spots which do not disappear with pressure) or bruises.
IV – Secondary lesions:
1- erosion:
It can be primary or secondary. It is a loss of superficial substance without underlying necrosis.
2- ulceration:
Deep loss of substance with destruction of the epithelium and the upper part of the chorion, the number, size, edges, bottom and base must be specified.
Ex: aphtha
3- scales: flakes of horny layer which detach from the EPIDERMIS (desquamation)
4- scabs: result from the coagulation of a serous, hemorrhagic or purulent exudate. At the oral level, they are mainly observed at the level of the lips.
5- fissures: linear erosions observed especially at the corners of the lips.
6- atrophy: thinning of the oral mucosa which appears smooth and varnished. Can be observed outside of any pathology in the elderly.
7- Pultaceous coatings: excessive desquamation of the epithelium forms so-called pultaceous coatings, coatings which are easily detached from the mucosa without hemorrhage.
8- Pseudomembranes: consist of desquamated epithelial cells, fibrin, inflammatory cells, microorganisms and food debris that are easily detached leaving a normal or red surface.
9-Scars: this is newly formed tissue that has repaired a deep loss of substance as in the case of scar tissue.
- Clinical examination:
Includes an exo oral (cervico-facial) examination and an endo oral examination. It should be noted that the appearance of lesions in the oral cavity is difficult to recognize due to:
o Histological characteristics of the oral epithelium (rapidly renewing)
o The nature of the oral environment: repeated microtraumas, permanent presence of saliva, frequency of superinfections, constant heat and chemical and thermal irritation.
The interrogation must seek:
• Age
• General background
• Concept of taking medication
• Alcohol and tobacco poisoning
• Notions of recent counting
• Circumstances and date of appearance of the lesions
• Duration, mode of evolution
• Functional discomfort and pain or notion of burning mucous membranes
• Concept of recurrence
• Previous treatment and their effectiveness
• General signs
- Cervico-facial examination:
we explore the entire skin covering without omitting the scalp, neurological functions (motor skills, sensitivity), underlying bone structures, and natural orifices (nostrils, external oral canals).
Palpation of the cervical lymph node areas is an essential part of the examination.
A general clinical examination of the skin covering in case of suspicion of systemic involvement.
- Examination of the oral cavity:
In good lighting, use a tongue depressor or mouth mirror to help spread the lips, corners of the mouth and tongue, and to visualize areas that are difficult to access with direct vision. Tweezers and a probe are also necessary.
- Mucosa and fibromucosa:
Very methodical, the inspection examines each region of the oral cavity from the outside to the inside even if the lesion appears at first glance.
Spread the lips outwards to clearly visualize the vestibular cul-de-sacs, as well as the folds between the cheek and the gums.
Similarly, the corners of the lips must be unfolded, examination of the palate is facilitated by the mouth mirror. Palpation of the lips, floor and cheeks can be done in combination with an exo buccal hand.
We finish with the examination of the soft palate, the tonsils and the posterior wall of the pharynx.
2. The tongue : A gentle protraction of the tongue, the tip of which is held by a compress, is useful for examining the faces and edges, as well as the floor of the mouth.
3. Salivary glands : bilateral parotid and submaxillary regions by inspecting their excretory orifices, and bimanual palpation will also be performed to assess the quality of the saliva.
4. Dental examination : by dental formula, CAD index, note periodontal lesions, coronal reconstructions, remove prostheses which sometimes can hide a lesion of the underlying mucosa. The occlusion will also be examined.
- Main criteria for describing an elementary lesion :
Palpation looks for pain, bleeding, softness or induration at the base especially when it is an ulceration, and finally its consistency.
3-Additional examinations :
The anamnesis and clinical study make it possible to limit the examinations to the strict minimum in the following:
● Local samples in an infectious hypothesis: direct examination and cultures (virological, bacteriological, mycological);
● Histological examination (biopsy) with, possibly, direct immunofluorescence examination in the case of autoimmune pathology.
● Serodiagnosis of bacterial or viral infections: apart from the serodiagnosis of syphilis, they are requested on a case-by-case basis, depending on the diagnosis mentioned.
Conclusion
The oral cavity can be the site of multiple lesions reflecting the general state of a dermatological pathology and which can be the first stage, hence the importance of knowing how to label them clinically despite the very often detected changes in these lesions and this in relation to the particularity of the oral environment.
Basic lesions in oral dermatology.
Cracked teeth can be healed with modern techniques.
Gum disease can be prevented with proper brushing.
Dental implants integrate with the bone for a long-lasting solution.
Yellowed teeth can be brightened with professional whitening.
Dental X-rays reveal problems that are invisible to the naked eye.
Sensitive teeth benefit from specific toothpastes.
A diet low in sugar protects against cavities.