Oral infections: viral and fungal

Question 1

Viral infections of oral importance (4)

Answer 1

Herpes viruses
– Simplex	1	and	2	
– Varicella	zoster	
– Cytomegalovirus	
– Epstein	Barr	
Coxsackie viruses
(Measles)
Human papilloma virus

Question 2

What is herpes simplex? (5)

Answer 2

• Enveloped, DNA virus, highly cytolytic,
infects via heparan sulphate
• Type 1 associated with skin and oral
mucous membranes
• Type 2 associated with genital mucosa
• Transmitted by droplet spread or intimate
contact
• 90-100% individuals have antibodies to
herpes simplex

Question 3

Herpes simplex type 1 - virus (4)

Answer 3

• Virus enters trigeminal sensory neurones
• Migrates to the ganglion by retrograde axonal flow
• Latency
- 50% of cases lies dormant

Question 4

Herpes simplex type 1 - reactivation (4)

Answer 4

In 30% of cases virus is reactivated
Migrates to peripheral nerve endings
Virus is shed
Reactivation can be caused by
•UV
•Stress
• Illness
•Immunosuppression

Question 5

Herpes simplex - primary gingivostomatitis - natural history (4)

Answer 5

– Children, young adults
– Incubation period 5 days
– Heal within	10-14 days	
– Many cases	are	subclinical and so	
asymptomatic

Question 6

Herpes simplex - primary gingivostomatitis - signs and symptoms (5)

Answer 6

– Malaise and fever
– Vesicles which ulcerate
– Secondary infection
– Erythematous gingivitis
– Extra-oral lesions

Question 7

Diagnosis of herpes simplex - primary gingivostomatitis (2)

Answer 7

• Made on clinical features

* Patients have a rising antibody titre to herpes simplex.

Question 8

Pathogenesis of herpes simplex - primary gingivostomatitis (3)

Answer 8

– Herpes virus replicates in epithelial cells
– causes epithelial cell destruction and
“ballooning” degeneration of cells
– Results in intra-epithelial vesicles

Question 9

Clinical features of herpes labialis (5)

Answer 9

– "Cold sore"
– Prodromal tingling	
– Vesicles at the muco-cutaneous junction	
– Ulcerate and crust over	
– Lasts 7-10	days

Question 10

How common is herpes labialis (1)

Answer 10

Occurs in 30% of patients

Question 11

Main difficulty in diagnosing herpes labialis (1)

Answer 11

Differentiating erythema multiforme

Question 12

Treatment for herpes labialis (3)

Answer 12

Effective in prodromal stage
Aciclovir cream (Zovirax)
Penciclovir

Question 13

What is herpes (varicella) zoster virus (4)

Answer 13

Type 3 herpes virus
Primary infection - chicken pox
Secondary lesion - shingles
Most commonly affects one of the divisions of the trigeminal nucleus

Question 14

3 phases of herpes zoster (3)

Answer 14

Pre-herpetic neuralgia
-pain in the affected division; may mimic dental pain
Rash
-unilateral vesicles; ophthalmic, maxillary, mandibular
-ulcers (mucosa); crusting lesions (skin)
-lasts 2-3 weeks
Post-herpetic neuralgia
-burning pain, affects 10-20%
-more common in the elderly

Question 15

Management of herpes zoster (4)

Answer 15

Aciclovir 800mg 5x daily, 7 days
– Valaciclovir	1g	3x	daily,	7	days	
– Famciclovir	250mg	3x	daily,	7	days	
Analgesics and other supportive measures
Referral to Ophthalmology if eye involved
Post-herpetic neuralgia
– Treat	pain	with	neuropathic	pain	drugs	
– Gabapentin,	antidepressants

Question 16

What is Epstein-Barr virus? (5)

Answer 16

HV4
Infectious mononucleosis
-tonsils
-petechiae on soft palate
-cervical lymphadenopathy
Burkitt's lymphoma
Nasopharyngeal carcinoma
Hairy leukoplakia

Question 17

Oral hairy leukoplakia (4)

Answer 17

Corrugated white patches
Bilateral on lateral borders of tongue
Seen in 25% of HIV infected patients
Can occur in non-HIV patients

Question 18

Diagnosis of oral hairy leukoplakia (1)

Answer 18

Demonstration of EBV in tissues

Question 19

Pathogenesis of cytomegalovirus (HV5) (2)

Answer 19

Inclusion bodies

Dormant in lymphocytes - interferences with MHC1 presentation

Question 20

Rare appearances of HV5 (2)

Answer 20

Glandular fever-like illness (no lymphadenopathy)

Salivary gland swelling

Question 21

HV5 in immunocompromised (3)

Answer 21

Large ragged oral mucosal ulcers
Salivary gland swelling
Retinitis

Question 22

HV5 in new born (1)

Answer 22

Life threatening

Question 23

Cocksackie A viruses - which cause the most problems? (4)

Answer 23

Types 4, 5, 10, 16

Question 24

Cocksackie A viruses - herpangina (6)

Answer 24

– CVA4	(occ.	Others)	
– Usually trivial; mild	febrile illness
– Young	children	and	young adults	
– Vesicles and ulcers	on	soft	palate	
– Lasts	a	few	days	
– Usually no	treatment	
• analgesic mouthwash		
• e.g Difflam

Question 25

Cocksackie A viruses - hand, foot and mouth disease (4)

Answer 25

``` – CV A16 – Similar to herpangina; mild systemic upset – Rash/vesicles on palms of hands and soles of feet – Intra-oral vesicles and ulcers ```

Question 26

Measles - what is it and features (5)

Answer 26

``` Paramyxovirus infection Systemically unwell Koplik’s spots – White papules on buccal and palatal mucosa during prodromal phase Skin rash Long term effects ```

Question 27

HPV - types (4)

Answer 27

``` > 40 types DNA virus - just 9 genes Only infects keratinocytes -basal cells - integrins "High risk" oncogenic subtypes -HPV 16 & 18 -cervica, oropharynx and anal cancer ```

Question 28

HPV - main oral lesions include (4)

Answer 28

Squamous cell papilloma/ verruca vulgaris Condyloma accuminatum Focal epithelial hyperplasia • HPV13 • Common in small native communities and HIV infection • Treatment – excision, imiquimod 5% cream Dysplasia/SCC - controversial

Question 29

Fungal infections (7)

Answer 29

* Aspergillosis * Blastomycosis * Candidosis * Coccidioidomycosis * Cryptococcosis * Histoplasmosis * Rhinosporidiosis

Question 30

Candida species (5)

Answer 30

* C.albicans - most common * C.tropicalis * C.krusei * C.glabrata * C.dubliniensis

Question 31

Predisposing factors to candida (4)

Answer 31

Prostheses - no exfoliation Low saliva Antibiotics - reduced bacterial competition Immuno-suppresion

Question 32

Predisposing factors to candida - low saliva (3)

Answer 32

No flow; reduces soluble defences | Low pH induced by high sugar diet

Question 33

Predisposing factors to candida - Immuno-suppresion (6)

Answer 33

``` – Very young/old – Diabetes – Corticosteroids, including steroid inhalers – Malignancy – HIV – Immunosuppressive therapy ```

Question 34

Pathogenic/ virulence factors (3)

Answer 34

Tissue invasion and pathogenesis Yeast to hyphal transition and growth is essential for virulence and pathogenesis Hyphae secrete candidalysin - a pore forming toxin that kills human cells and also initiates an immune response Proteases - Secreted Aspartyl Proteases (SAP) used to invade between/ through epithelial cells -sap 1-3 - needed for mucosal infection -sap 1-3 - degrade complement -sap 4-6 - contribute to systemic infection

Question 35

Classification of candida infections (4)

Answer 35

Acute forms Chronic forms Candida-associated lesions HIV-related candidosis

Question 36

Acute forms of candida (2)

Answer 36

– Acute pseudomembranous candidosis (Thrush) | – Acute atrophic candidosis (antibiotic sore mouth)

Question 37

Chronic forms of candida (3)

Answer 37

– Chronic atrophic candidosis (denture stomatitis) – Chronic hyperplastic candidosis (candidal leukoplakia) – Chronic mucocutaneous candidosis (various: inherited syndromes)

Question 38

Candida-associated lesions (2)

Answer 38

– Median rhomboid glossitis | – Angular cheilitis

Question 39

Acute pseudomembranous candidosis (2)

Answer 39

Creamy thick white plaques -thick biofilm of yeast and hyphal forms Easily rubbed off

Question 40

Causes of acute atrophic candidosis (2)

Answer 40

– Prolonged corticosteroid or antibiotic therapy – Bacterial flora altered, allows candida to flourish

Question 41

Treatment of acute atrophic candidosis (1)

Answer 41

Reduce antibiotic use if possible

Question 42

Management of acute atrophic candidosis (3)

Answer 42

``` Confirm diagnosis – Swab(s) or oral rinse +/- MC+S Investigate and treat underlying cause Treat with anti-fungal agents – Topical • Miconazole oral gel • Nystatin suspension • Amphotericin B (only available in hospital pharmacies) – Systemic • Fluconazole • Itraconazole ```

Question 43

Denture related candidosis (3)

Answer 43

``` Palate protected from saliva Poor denture hygiene Treatment – Improve denture hygiene • Leave out at night • Clean denture and soak in Milton or Corsodyl – Antifungals • Nystatin +/- Miconazole gel to fitting surface tds • 2-3 weeks ```

Question 44

Median rhomboid glossitis (5)

Answer 44

``` • Erythematous area on dorsum tongue • Epithelial proliferation • Candida in epithelium • Not premalignant • Diagnosis usually on clinical grounds ```

Question 45

Angular cheilitis (3)

Answer 45

``` • Reduced vertical dimension – drooling of saliva • Haematological deficiency – Iron, B12, folate deficiency – Crohn’s disease • Some cases associated with Staph. aureus ```

Question 46

Treatment of angular cheilitis (2)

Answer 46

– Address underlying cause | – miconazole cream or fusidic acid, depending on cause

Question 47

Chronic hyperplastic candidosis (5)

Answer 47

``` • White or red/white patch, nodular • Can’t be rubbed off • Labial commissures or tongue • Premalignant: – “Candida leukoplakia” – up to 25% risk of malignant change. • Diagnosis by biopsy ```

Question 48

Aetiology of chronic hyperplastic candidosis (4)

Answer 48

``` – Usual candida risk factors – Smoking – Not clear if candida cause the lesion or invade a preexisting lesion. – Some lesions regress following antifungal therapy ```

Question 49

Management of hyperplastic candidosis (3)

Answer 49

• Diagnosis – Biopsy will establish diagnosis – Assess degree of dysplasia and risk of malignant transformation • Treatment – Systemic antifungals • 7-14 days fluconazole or amphotericin B – Smoking cessation • If no improvement and high risk of malignant transformation then excise