Oral Patho Lec 5 by Tala Mazahreh

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Oral Patho Lec 5 by Tala Mazahreh

Post by Sura on 24/10/2011, 2:44 am

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Re: Oral Patho Lec 5 by Tala Mazahreh

Post by Shadi Jarrar on 5/11/2011, 6:00 pm

Oral Pathology lecture # 5

17/10/2011

Tala Mazahreh

Human Immunodeficiency Virus (HIV) and AIDS

-HIV is an RNA virus that attacks lymphocytes, monocytes and certain nerve cells.

-Infection by HIV involves binding to CD4 receptors of T-helper lymphocytes.



PGL

The clinical response to HIV infection is demonstrated as follows:






AIDS

Exposure à Infection à HIV seropositive



ARC






PGL:Persistent Generalized Lymphadenopathy

ARC:AIDS-related complex

Oral manifestations:

There is no specific oral manifestations that appear exclusively in HIV patients, those that appear are the same for immunocompromised patients whether due to drugs, or primary immune deficiency, or due to HIV infection. Oral manifestations are divided into 3 groups based on the strength of their association with HIV infection, and here is a description of some of the oral manifestations that appear in AIDS patients:

1. Candidosis:

-Which is the most important oral manifestation occurring in HIV-infected patients.

-Seen in 20% of HIV seropositive patients, and up to 70% of patients that developed AIDS.

-It is not confined to the oral cavity, candidosis can also be seen in the GIT and respiratory tract

-It is persistent and refractory to treatment.

-Candidal infection is mainly due to Candida Albicans, but other species may have a role as well.

-It may be seen in many forms such as thrush which is the most common that appear as chronic persistent lesions, or chronic erythematous candidosis , or chronic hyperplastic candidosis.



2. HIV-associated periodontal diseases:

v Linear gingival erythema:

Persistent erythema in the area 1-2 mm from the marginal gingival.

v NUG (Necrotizing Ulcerative Gingivitis):

Destruction of the marginal gingiva and interdental papilla.

v Necrotizing Ulcerative Periodontitis:

Destruction of the periodontium, loss of alveolar bone, destruction & necrosis of the gingiva.



3. Hairy Leukoplakia:

-Clinically appear as linear, folded and raised hairy-like projections (although sometimes it may be smooth).

- Appear mainly on the lateral border of the tongue (and less frequently on the buccal mucosa)

- Whitish in color

- Usually bilateral (but may be unilateral).

-Again this is not exclusive to AIDS patients, it is also seen in immunocompromised patients such as renal transplant patients taking immunosuppressive drugs, and also reported upon steroid administration, and can be even seen in some immune competent patients.

-It is considered a precursor to AIDS and its appearance is an indication that the number of T-helper cells has fallen below 200/mm³ , so if we see it in a patient which is HIV-seropositive, this means that he is soon going to progress to the final stage of infection (fully developed AIDS).



-Histologically:

-It appears whitish in color due to hyperparakeratosis and acanthosis forming the finger-like projections.

- No inflammatory cells although it is an infection caused by Epstein-Barr Virus and sometimes there’s also superinfection by candida, but the reason for absence of inflammatory cells is that the patient already has damaged cell-mediated immunity.

-But the features of viral infection can be seen in the superficial prickle cell layer, such as clearing around the nucleus in cells called koilocytes or koilocyte-like cells.

-Using stains we can see other types of organisms such as candida, which are secondary or super-infection in this case and are not the cause of the lesion.

-To confirm that the lesion is caused by Epstein-Barr virus there are some investigations that can be done such as: In-situ Hybridization, PCR, and immunohistochemistry (to find the virus within the tissues).



4. Kaposi’s Sarcoma

-Present before the emergence of AIDS

-Endemic and mainly seen in Africa

-Not lethal, and usually multiple tumors are seen.

-Most common tumor affecting AIDS patients (about 25% of AIDS patients will develop Kaposi’s sarcoma).

-Most commonly seen in males, white, and homosexuals.

-Affecting the skin and mucous membranes.

-May be single or multiple(which is not common for tumors)

-Painless

-Appear as macules, papules, nodules or ulceration

-Appears red, pink or violet in color on the tip of the nose (which is the most commonly affected area in the head and neck region).

-In the oral cavity, it has the same appearance that appears on the skin, and usually seen on the palate and maxillary gingival. Appears as macules, patches, nodules or may become ulcerated causing destruction for the surrounding area.



Histologically

Ø In the early stage, it resembles hemangioma or pyogenic granuloma, mainly composed of tissues containing endothelial cells, extravasated RBC’s and small irregular vascular spaces and spindle-shaped cells(which are a unique feature of Kaposi’s Sarcoma). So mainly in the early stage it may be confused with other benign lesions.

Ø In the late stage it consists mainly of spindle-shaped cells and the other components become less in number.

In immunohistochemistry , spindle-shaped cells can be seen containing Human Herpes Virus 8( Kaposi Sarcoma-associated Herpes virus) which is the cause of this tumor.



5. Non-Hodgkin’s Lymphoma

-Second most common tumor after Kaposi’s Sarcoma in AIDS patients.

-Related to Epstein-Barr Virus.

-Mainly affecting the maxillary tubrosity area and the adjacent gingiva, and the palate.

-It is a malignant tumor causing swelling, nodularity , ulceration, destruction , necrosis and mobility of teeth.



6. Atypical Ulceration

-Less commonly associated with HIV-infected patients

-Resembles aphthous ulcer

-Mainly seen in the posterior part of the oral cavity

-Caused by either infections such as viral (Herpes and Cytomegalovirus) or bacterial (mycobacteria), or tumors .



7. Idiopathic thrombocytopenia Purpura

-Appears on mucous membranes as petechiae and ecchymosis, and have a high tendency to bleeding



8. HIV-associated salivary gland disease

Such as: -chronic parotitis

-Sjogren’s like syndrome

-Parotid swelling

-Lymphoepithelial cystic lesions



9.Viral Infections

Recurrent and persistent viral infections are usually seen in AIDS patients.

-Severe Herpes and Herpes zoster, intra oral herpes and recurrent Herpes labialis, Human papilloma virus causing Verruca Valgaris and Condyloma Accuminatum.

10.Bacterial Infections (TB)

11. Fungal Infections (Deep mycosis)

12. Melanocytic hyperpigmentation (caused by destruction of the adrenal gland or drugs).

13. Neurological Disorders (Facial paralysis)







Oral Ulcerations

Ulcerations are common lesions seen frequently among patients and it is the loss of epithelium and the exposure of the inflamed connective tissue, while erosion is defined as loss of part of the epithelium and it usually appears red in color, while an ulcer appears white as a result of exposure to the connective tissue and the deposition of fibrin.

Ø Causes of oral ulceration:

1. Infection

-Viral (Herpes Zoster)

-Bacterial (TB and Syphilis)

-Fungal (Deep mycosis but NOT Candida)

2. Traumatic

3. Associated with systemic disease

-Hematological (Neutropenia, lymphoma, leukemia)

-GIT (Crohn’s , ulcerative colitis)

-Behcet’s disease

-HIV

4. Associated with dermatological disease

Such as lichen planus, chronic discoid lupus erythematosus , and vesiculobullous disorders (Pemphigus)

5.Neoplastic (Squamous cell carcinoma, Kaposi’s sarcoma and Non-Hodgkin’s lymphoma)

6. Idiopathic (recurrent aphthous ulceration)







Traumatic Ulcer


*Mechanical

Not caused by chronic mild irritation, but by acute trauma, caused by a sharp edge of a denture, appliance or even a restoration, it may also be caused by the dentist himself after perio treatment or by polishing disks….etc

For diagnosis: a reason for irritation must be found in the region close to the place of the ulcer, and the cause must be corresponding to the ulcer’s shape , size and site. For example, for diagnosis of a traumatic ulcer on the lateral border of the tongue, a fractured tooth, restoration or any sharp edge must be found in an area close to the lesion.

This type of ulcers usually heal upon removal of the cause within (10 -14) days.

No need for biopsy for diagnosis, because this is a non-specific ulcer, so all what we’ll see in a histological section is sloughed epithelium and granulation tissue and inflammation in the lamina propria, and diagnosis is based on clinical examination.



*Chemical

-Such as aspirin misuse by the patients by placing the aspirin tablet directly on the oral mucosa next to the painful tooth for example, so the acid content in the tablet will cause necrosis and ulceration in that area.

-There are several other chemicals used in dental practice that may cause oral ulcerations such as formocresol, calcium hydroxide, itching agents…etc, so care should be taken while using any irritant subject and avoid contact with the oral mucosa.



*Thermal

After eating or drinking hot substances and this usually causes erosin rather than ulceration.



*Factitious

Are self-inflicted ulcerations, where the patient himself induces oral ulceration by biting his tongue or buccal mucosa, or using his nails or a sharp instrument. And these patients are usually mentally retarded or are found to be suffering from anxiety or depression.



*Radiation

In patients undergoing radiotherapy for head and neck cancer, this may cause immediate damage to the epithelium, and the area will become red, edematous and burning sensation will occur. Then the area might heal but will become ulcerated again after a while due to damage to the blood vessels in this area causing ischemia and necrosis in the overlying epithelium.



*Eosinophilic Ulcer

-An unusual type of chronic ulcer, thought to be caused by crushing injury to the muscles especially in the tongue.
-Histologically, lymphocytic infiltration deep in the muscle tissue, especially eosinophils. But the etiology and pathogenesis are still not completely known.




Recurrent Aphthous Stomatitis (RAS)


-When none of the above mentioned causes can be identified as the cause of a present ulcer, thus we classify it as an idiopathic aphthous ulceration.

-It is easily diagnosed upon clinical examination.

-Recurrent.

-Very commonly seen among young patients.

- 10-25% of people have encountered an aphthous ulcer at one point in their lives.

-In a study done among JU students, 37% had a positive history of aphthous ulceration during the year before and 5% had ulcerations at the time of the study.

-Onset is usually during the first 2 decades of life. So it is not unusual to see this type of ulceration among children.

-No difference between prevalence among males or females.

-Usually non-smokers are more susceptible to encounter aphthous ulcerations, and this may be due to hyperkeratinization of the epithelium in the oral cavity of smokers, rendering the mucosa more resistant to damage by immune cells ( since aphthous ulcer is caused by cell-mediated immunity that causes destruction to the epithelial cells).

So many patients encounter aphthous ulceration upon cessation smoking.

-Prodromal symptoms may precede the occurrence of an ulcer, and these include redness, edema, and burning sensation.

-Symptoms : Pain and difficulty during eating.
-Diagnosis: based on history and clinical examination and does not need a biopsy.


Clinical forms:

1.Minor aphthous Ulcer:

-80% of the cases.

-Appear more than one at a time (up to 5 ulcers together).

-Seen on the buccal mucosa, labial mucosa, and tongue. But not on keratinized mucosa such as the hard palate.

-Shape: Round or oval, shallow, grayish in color, and surrounded by red margins.

-Duration: 10-14 days and heals without scarring.

-Recurrence rate: 1-2 times/year



2.Major aphthous ulcer:

-Usually larger in size and it’s deeper than the minor type.

-Longer duration

-2nd most common.

-May occur as 1 to 10 ulcers at a time

-Usually in the posterior part of the oral cavity as in the tonsils, soft palate and the palatoglossal arch but may occur at any site in the oral cavity (even on the keratinized mucosa as in the palate and gingiva)

-usually > 1cm in diameter (while the minor type is usually <1cm in diameter).

- It persist for a longer duration(may persist for about one month) and will heal with scarring.

-Recurrence rate is higher (once every month), leading to difficulty in eating and constant irritation.

3.Herpitiform Ulcer

-Least common type

-Named so because it resembles herpes

-Multiple ulcers may reach up to 100 ulcers at one time

-Very small lesions that unite together and form an irregular shape.

-May be confused with primary herpetic gingivostomatis, but inflammation in the gingiva or systemic signs and symptoms such as fever and malaise and lymphadenopathy are not seen in aphthous ulceration as in the other viral infections.

-Shallow and irregular in shape.

-Surrounded by red margins.

-May persist for 2-3 weeks and healing occurs with scarring.

-High recurrence rate (every month).
J THE END J
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Shadi Jarrar
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