2. Oral candidosis Flashcards
What structure is fungi? E or P?
Eukaryotic- contain nucleus, mitochondria and Golgi
What is the cell wall of fungi made of?
Chitin, mannan, glucan and structural proteins
What are the different types of yeast?
Mould like or yeast like, or dimorphic
What do yeast like fungi grow like?
They bud and detach, and behave like bacterial colonies
What do mould like fungi grow like?
They form hyphae, intertwining masses and fluffy colonies
What type of yeast does oral candida involve?
Dimorphic
What is dermatophyte fungi?
Superficial infections such as ring worm, athlete’s foot
What is opportunistic fungi?
Found in normal microflora but can cause disease in compromised host. Eg, candida, aspergillus spp
What are systemic fungi?
Cause disease in individual even if they are healthy, eg Blastomyces
What type of fungi is candida?
Dimorphic, opportunistic (commensal), superficial mycosis
Where is the main reservoir for candida?
Dorsum of tongue
What shape is yeast like fungi?
Ovoid
What shape is true hyphae?
Elongated tubes
What is pseudohyphae?
Elongated tubes which have constrictions along their length and attach together to form branching structures
What is the name of the most common candida species?
C.albicans
What candida is associated with malignant transformation?
C. Krusei
What are predisposing factors to candida?
Age, local factors, xerostomia, drugs, systemic disease
What are non-specific factors that protect from oral candida?
- Shedding of epithelial cells
- Salivary flow washing surface away
- Phagocytic activity of macrophages and neutrophils
- Commensal bacteria which keeps other bacteria in check
- Saliva has antimicrobial properties including histidine rich polypeptides, lactoferrin, lysozyme, sialoperoxidase
What does saliva contain that creates non-specific protection?
Sialoperoxidase, lactoferrin, histidine rich polypeptides, lysozyme
What are specific factors protecting from oral candida?
- IgA secreted in saliva prevents adhesion of fungi
- specific antibodies in serum may end up in oral cavity through cervical fluid
- antimicrobial peptides- defensing
- cell mediated responses
What are local factors predisposing to candida?
Mucosal trauma
Denture wearing
High carbohydrate diet
Tobacco smoking
What are age factors predisposing to oral candida?
Neonates and Elderly most affected
What types of drugs predispose to candida?
- broad spectrum antibiotics
- immunosuppressant therapy
- steroids
- cytotoxic agents
What can cause xerostomia?
- Drugs
- Radiotherapy to the head and neck
- Sjogren’s syndrome
What systemic diseases have a link to candida?
Iron deficiency anaemia
Acute leukaemia
Diabetes
HIV/AIDS
Immunodeficiency states
What is the mechanism of infection of fungi?
- Proteinases and phospholipases help to break down phospholipid bilayer so fungi can invade
- Fungi metabolism produce nitrosamines which are linked to carcinogenic changes
- Fungi have extracellular mannoprotein which allows adherence to the acrylic and epithelium
- Tubular hyphae form adhesion to epithelium
What are the 2 types of acute candidosis?
Pseudomembranous- white and erythematous (atrophic)- red
What are the 2 types of chronic candida?
Erythematous (red)
Hyperplastic (Candida leukoplakia, CHC)- white
What are 3 examples of candida associated lesions?
Denture stomatitis, Angular chelitis, median rhomboid glossitis
Explain what acute pseudomembranous thrush looks like?
Thick white coating, milk curds
Can be wiped off with gauze leaving underlying red base
What local factors can cause acute pseudomembranous thrush?
Antibiotics, corticosteroids (inhalers), salivary gland disease
What systemic factors can cause acute pseudomembranous thrush?
Systemic steroids, diabetes, anaemia, leukaemia, malignancy, HIV
What can be used to stain candida?
- Periodic acid schiff- stains glycogen in cells and fungi as magenta
- Wilder silver method- stains black
What does acute erythematous candida look like?
Red, painful, depapillated tongue
Palate is sometimes involved
Where the mucosa touches the palate, you may get a kissing lesion
What other disease can acute erythematous candida also look like?
Black hairy tongue- antibiotics can alter the oral flora balance, allowing candida to proliferate
What does CHC look like?
Leukoplakia- persistent white patch that cannot be removed by scrapping.
Sometimes has red areas too-speckled.
Where is CHC most often found?
Buccal mucosa, palate and tongue
What is it called when there are multiple sites of CHC?
Chronic multifocal oral candidosis
What is the histology of CHC?
- Increase in thickness of the parakeratotic layer of epithelium
- Acanthosis- increase in thickness of the prickle cell layer with neutrophils and chronic inflammatory cells
- Oedema
- Microabscesses in the epithelial layer
- Lamina propria contains chronic inflammatory cells- lymphocytes, macrophages, plasma cells
Is CHC premalignant?
50% of cases of CHC may show epithelial dysplasia. The dysplasia may go away after treatment.
What layers do candidal hyphae invade in CHC?
The parakeratinised layer, but not the prickle cell layer so it is a superficial infection.
What is the appearance of the nucleus in the parakeratinised layer in CHC?
Contains nuclei of epithelial cells- longest axis of the nucleus runs parallel to the surface of the epithelium. Nuclei are flat and dark.
What is candida-associated denture stomatitis?
Due to wearing ill-fitting dentures
Usually asymptomatic
Not cleaning dentures- leads to accumulation of debris that can lead to candida proliferation
Chronic oedema and erythema of denture covered mucosa
Seen in pt’s with high carbohydrate diet
What are Newton’s 3 types of candida-associated denture stomatitis?
- Pinpoint (localised) erythematous areas
- Diffuse erythematous areas
- Chronic inflammatory papillary hyperplasia- erythema
What is angular cheilitis?
Sore, erythematous fissured corners of the mouth
What other diseases are associated with angular cheilitis?
Iron, riboflavin, folic acid, B12 deficiency
30% of patient’s with denture stomatitis have it
What is angular cheilitis caused by?
Multifactorial- candida
Bacteria- Staphylococcus aureus, Streptococcus beta haemolytic sp
What is median rhomboid glossitis?
Found in midline dorsal tongue- often has kissing lesion on the palate
- Type of candida infection
What is the appearance and histology of median rhomboid glossitis?
Rhomboid shape, devoid of papillae, nodular
- Lack of filliform papillae, parakeratinised, acanthotic epithelium, neutrophil infiltration and superficial microabscess formation
What is systemic mucocutaneous candidosis?
Persistent candida infection of mucosa, nails, skin
Oral lesions are similar to CHC
What is candidosis endocrinopathy syndrome?
You see systemic mucocutaneous candidosis, enamel hypoplasia, autoimmune endocrinopathies, hypoparathyroidism, diabetes mellitus, adrenocortical hypofunction
What is the treatment for candida?
Treat underlying cause
Antifungals- nystatin, fluconazole, amphotericin
If there is CHC and epithelial dysplasia, you need to follow up
